United States Court of Appeals
                     For the First Circuit

No. 13-1730

                    UNITED STATES OF AMERICA,

                            Appellee,

                               v.

                     WILSON SERRANO-MERCADO,

                      Defendant, Appellant.


          APPEAL FROM THE UNITED STATES DISTRICT COURT

                 FOR THE DISTRICT OF PUERTO RICO

       [Hon. Carmen Consuelo Cerezo, U.S. District Judge]


                             Before

                  Thompson, Lipez, and Barron,

                         Circuit Judges.



     Raul S. Mariani-Franco for appellant.
     Francisco A. Besosa-Martínez, Assistant United States
Attorney, with whom Rosa Emilia Rodríguez-Vélez, United States
Attorney, and Nelson Pérez-Sosa, Assistant United States Attorney,
were on brief, for appellee.



                           May 1, 2015
            BARRON, Circuit Judge.        Wilson Serrano-Mercado contends

the District Court made two mistakes in sentencing him for a

federal gun crime.    First, he argues the District Court erred in

counting more than one of his prior convictions for Puerto Rico

criminal offenses as a conviction for a "crime of violence" under

the Sentencing Guidelines.       Second, he contends the District Court

gave too much significance under those same guidelines to the

existence of an obliterated serial number on the frame of the

firearm he was convicted of possessing, when the serial number on

the slide was unaltered. We hold the District Court did not commit

reversible error in either respect and thus affirm the sentence

imposed.

                                     I.

            In District Court, Serrano pled guilty to being a felon

in knowing possession of a firearm -- a 9mm pistol.                18 U.S.C.

§§ 922(g)(1), 924(a)(2).         The Sentencing Guidelines specify a

suggested   sentencing   range    for     such   a   conviction.    U.S.S.G.

§§ 2K2.1, 5A.    Serrano rests his challenge to his sentence on the

two errors that he claims the District Court made in identifying

the proper range.        And thus, it is helpful to provide some

background about how, in general, such ranges are identified, and

then how, in particular, the range was identified here.

            Under the guidelines, two variables provide the basis for

the sentencing range.      The first variable is called the offense


                                    -2-
level.   It is expressed in terms of a point score.    

  The

score is a function, initially, of what is known as the base

offense level.    

introductory cmt.   The base offense level

is generally calculated with reference to the nature of the crime

of conviction.     The guidelines then add points to or subtract

points from the base offense level for various enhancing or

mitigating factors that may or may not be present in a defendant's

case.    The result is the total offense level.

            The second variable is a defendant's criminal history

category.    

   The guidelines assign criminal sentences

certain point values.      

      These points are then

translated into one of six criminal history categories, represented

by the use of a Roman numeral from I to VI.       

  The more

severe the criminal history a defendant has on the basis of the

points assigned, the higher the category.

            On the basis of these two variables, the guidelines then

set forth suggested sentencing ranges in a chart.     

of

the chart lists possible total offense levels.        The other axis

lists possible criminal history categories. At the intersection of

every possible value for these two variables, the chart sets forth

a suggested range of sentences.

            Before actually imposing a sentence, a district court

often receives input from various actors about how to calculate the

defendant's guidelines sentencing range.        If there is a plea


                                  -3-
agreement, as there was here, the agreement will often recommend a

range.   And, in setting forth that recommendation, the agreement

will often set forth certain facts that bear on the calculation of

the base offense level, the total offense level, and the criminal

history category.   See Fed. R. Crim. P. 11(c)(1).

          The district court will also have the benefit -- as,

again, was true here -- of a probation officer's pre-sentence

report, which is based on that officer's investigation.       That

report, too, will set forth facts bearing on the sentencing

guidelines calculation.    And that report may, in light of those

facts, suggest a calculation different from the plea agreement.

See Fed. R. Crim. P. 32(d).

          The district court need not accept the calculations in

the plea agreement or the pre-sentence report.       Nor must the

district court choose a sentence that falls within the range the

district court's own guidelines calculation yields, though the

sentence must comply with additional substantive and procedural

limitations.   See 18 U.S.C. § 3553; United States v. Booker, 

, 245, 261 (2005).     But if the district court errs in

making the guidelines calculation, the sentence may be reversed

even though that calculation does not directly compel the sentence.

See Gall v. United States, 

, 51 (2007); United States v.

Tavares, 

, 25 (1st Cir. 2013).   And that is what Serrano

argues must happen here.


                                -4-
             In this case, the plea agreement recommended a sentencing

range tied to a base offense level of 22.        The agreement made that

calculation because it stated that Serrano had been convicted of

one prior felony for a "crime of violence" at the time of his

unlawful firearm possession.         U.S.S.G. §§ 2K2.1(a)(3), 4B1.2(a).

The   plea   agreement   did   not   identify   any   of   Serrano's     prior

convictions.     The plea agreement thus did not specify which one

qualified as the crime of violence that warranted that base offense

level of 22. The plea agreement's calculation also did not include

a   four-point   increase   under    the   guidelines'     enhancement    that

applies when the firearm involved in a felon-in-possession charge

has "an altered or obliterated serial number."           

K2.1(b)(4).1

             The probation officer's pre-sentence report, as amended,

departed from the plea agreement's guidelines calculation.             And it

did so in two respects.

             First, the amended pre-sentence report suggested a base

offense level of 24, rather than 22.         The report used that higher

base offense level because it stated that Serrano actually had more

than one prior felony conviction for a "crime of violence."                

4B1.2(a).       The report did not expressly identify

which of Serrano's prior convictions qualified as a crime of



      1
       The plea agreement also included a clause waiving Serrano's
appeal rights, but only if the court accepted the plea's sentencing
recommendation. Because the court did not, the government concedes
that the plea agreement's appeal waiver does not apply.

                                     -5-
violence.     The report thus did not identify the ones the report

relied upon in setting the base offense level at 24.

             The    report     did    list,     however,     a       number   of   prior

convictions for Serrano.           These convictions included a 2006 Puerto

Rico conviction for assault that the parties both appear to agree

does qualify as a conviction for a crime of violence.                              These

convictions also included a 2005 Puerto Rico conviction under

Article 3.1 of Law 54, Puerto Rico's Domestic Abuse Prevention and

Intervention       Act,    P.R.    Laws   Ann.   tit.   8,       §    631,    which   the

government on appeal now contends also qualifies but which Serrano

argues does not.          And, finally, the list included an earlier 2004

conviction that the government does not argue qualifies.

             The second respect in which the pre-sentence report

differed    from    the     plea   agreement     concerned       the    serial-number

enhancement.       Unlike the plea agreement, the report concluded the

enhancement did apply.            The report thus increased its calculation

of the total offense level by four points. U.S.S.G. § 2K2.1(b)(4).

             The District Court adopted the pre-sentence report's

recommendations regarding the guidelines calculation. The District

Court stated Serrano had "two domestic violence convictions and one

assault conviction which meet the guidelines criteria for crimes of

violence."     The District Court thus started from a base offense

level of 24 because it had found, contrary to the representation in

the plea agreement, that Serrano had been convicted of more than


                                          -6-
one offense that qualified as a crime of violence.               The District

Court       then   applied   the    four-point   serial-number   enhancement.

Finally, and consistent with the plea agreement and the pre-

sentence report, the District Court subtracted three points for the

defendant's acceptance of responsibility, U.S.S.G. § 3E1.1 cmt. 3,

due to the plea.

               The District Court thus arrived at a total offense level

of 25.       The District Court also determined Serrano had a criminal

history category of V.             These calculations then combined to set

Serrano's guidelines sentencing range between 100 and 125 months.

The District Court imposed a sentence at the lower bound of that

range: 100 months.

               On appeal, Serrano argues for the first time that his

base offense level should have been 22, not 24.2           He contends that



        2
        Serrano argues on appeal that he raised an objection below,
but we conclude otherwise. Serrano did object to the first pre-
sentence report's "total adjusted offense level [of] 23 when the
plea agreement establishes a total offense level of 19."        But
nothing in the record indicates that this general objection to the
unamended pre-sentence report's total offense level was an
objection to counting the 2005 felony under Article 3.1 -- or any
other prior offense -- as an additional crime of violence for
purposes of determining the base offense level. Indeed, the pre-
sentence report's addendum relates that when, following Serrano's
lodging that general objection, the probation officer explained his
view that Serrano had two prior convictions for crimes of violence,
Serrano did not offer an objection or contrary argument.       And,
finally, Serrano did not object when the District Court stated at
sentencing that it was applying the base offense level of 24
because Serrano had at least two prior convictions for a crime of
violence, including not only one for assault but two for domestic
violence.

                                        -7-
the lower base offense level is the right one because his 2006

felony    conviction   for    assault   is   the   only   one    of   his   prior

convictions that qualifies as a crime of violence under the

guidelines. Serrano also argues, as he did below, that the serial-

number enhancement cannot apply because even though one serial

number on the gun's frame was obliterated, another serial number on

the slide remained unaltered.           For that reason, he contends the

District Court erred in adding four points to his total offense

level.3

            If the District Court had used a base offense level of 22

and had not applied the serial-number enhancement, then, after the

deduction for acceptance of responsibility, Serrano's total offense

level would have been 19. With his criminal history category of V,

his guidelines sentencing range would have been 57 to 71 months in

prison.     U.S.S.G.   §     5A.   Under     the   District     Court's     actual

guideline calculation, by contrast, the range was 100- to 125-

months.




     3
       Serrano's opening brief referenced a third potential ground
for challenging the sentence: ineffective assistance of counsel.
But Serrano raised this argument only in the statement of issues on
appeal and did not advance the argument in the body of the brief.
His reply brief made clear that the ineffective-assistance argument
was erroneously added to the statement of issues in the first
brief. We thus do not address it further.

                                    -8-
                                      II.

             Serrano's first challenge is to the District Court's

conclusion that his base offense level was 24 because he had two

prior felony convictions that counted under the guidelines as

convictions for a "crime of violence."         We start by describing how

we usually decide whether a prior conviction is for a crime of

violence.      We then explain the problem with using that same

approach here, given Serrano's failure to preserve the argument by

properly raising it below.

                                      A.

             Ordinarily,   we   use     what   the   precedents   call   a

"categorical approach" to decide if a defendant's prior felony

conviction was for a crime of violence.          United States v. Jonas,

, 86 (1st Cir. 2012).               Under this approach, the

conviction counts as one for a crime of violence if the elements of

the conviction fit the guidelines' definition of a crime of

violence. 

Otherwise, the conviction does not count,

no matter what the facts show the defendant actually did in

committing the crime -- even, that is, if those facts show he acted

violently.    

             This focus on the elements of the conviction -- rather

than the underlying conduct -- fits with the text of the Sentencing

Guidelines, which makes the base offense level for the felon-in-

possession offense turn on prior "convictions of . . . a crime of


                                      -9-
violence,"     not    on    prior   conduct.           U.S.S.G.        2K2.1(a)(2),(3)

(emphasis added); see Descamps v. United States, 

,

2287 (2013).      And this approach also ensures present sentences are

not based on documents that could be quite old, might be uncertain

or disputed, and may contain factual allegations the defendant did

not contest at the time for any of a number of reasons unrelated to

the accuracy of the allegations.              

.

             In some cases, though, this categorical approach runs

into   a   potential       obstacle.       That   obstacle            arises    when    the

conviction    is     for   a   crime    set    forth    in    a       statute    that    is

"divisible."         A divisible statute is one that "sets out one or

more elements of the offense in the alternative -- for example,

stating    that    burglary     involves      entry    into       a    building    or    an

automobile."       

       The problem such a statute poses is

that these alternative elements may create distinct offenses, each

of which may or may not itself be a crime of violence.

             To deal with this wrinkle, we employ what the precedents

call -- not surprisingly -- a "modified categorical approach."

Under this approach, we look to limited materials, often called

Shepard documents, from the convicting court, such as charging

documents, plea agreements, plea colloquies, and jury instructions.

2284 (relying on Shepard v. United States, 

(2005)).     We do so not to determine the conduct the defendant

engaged in while committing an offense, as such conduct is of no


                                        -10-
relevance. We instead inspect these materials in order to identify

(if   such    identification       is     possible)   the   actual     offense      of

conviction     from    among   the      distinct    offenses     set   forth   in   a

divisible statute.       

             Once we identify the distinct offense of conviction by

consulting     the    materials,     we    then    return   to   the   categorical

approach.      We consider whether the elements of that distinct

offense meet the definition of a "crime of violence."

             All of which brings us to the final stage in this

process: the analysis of how the elements of the offense of

conviction match up with the guidelines' definition of a "crime of

violence."     A conviction for an offense qualifies as a conviction

for a crime of violence if the elements of the underlying offense

satisfy either (or both) of two clauses set forth in the relevant

guideline and that offense is punishable by more than a year in

prison.      U.S.S.G. § 4B1.2(a); see also U.S.S.G. § 2K2.1 cmt. 1

(cross-referencing the definition in § 4B1.2 to determine the base

offense level of the felon-in-possession crime).4

             The guideline's first clause provides that a crime of

violence is "any offense under federal or state law . . . that



      4
        "This definition is nearly identical to the definition of
a 'violent felony' contained in the Armed Career Criminal Act
(ACCA), 18 U.S.C. § 924(e)(2)(B). Recognizing this resemblance,
courts consistently have held that decisions construing one of
these phrases generally inform the construction of the other."

.

                                          -11-
. . . has as an element the use, attempted use, or threatened use

of physical force against the person of another."              U.S.S.G.

§ 4B1.2(a)(1).       This so-called "force clause" requires that the

offense of conviction include as an element "violent force," that

is, "force capable of causing physical pain or injury to another

person."    Johnson v. United States, 

, 140 (2010).      If

the offense of conviction does not involve the "use, attempted use,

or threatened use" of such violent physical force -- as may be the

case with an offense of common-law battery, whose force element can

"be satisfied by even the slightest offensive touching" -- then

that offense does not meet the requirements of the force clause.

            The guideline's second clause provides that a prior

felony conviction qualifies as a crime of violence if it is for

"any offense under federal or state law . . . that . . . is

burglary of a dwelling, arson, or extortion, involves use of

explosives, or otherwise involves conduct that presents a serious

potential     risk   of   physical   injury   to   another."   U.S.S.G.

§ 4B1.2(a)(2).       Even if an offense does not fall under the force

clause, therefore, that offense qualifies as a crime of violence if

it matches one of these enumerated crimes or otherwise satisfies

the requirements of the guideline's so-called "residual clause."




                                     -12-
                                          B.

             In applying this framework, we begin by noting the

parties agree that Serrano's 2006 conviction for assault under

Puerto Rico law does count as a conviction for a crime of violence.

We also note that Serrano does not dispute that the District Court

counted the 2005 conviction for domestic violence under Article 3.1

in finding that Serrano had more than one conviction for a crime of

violence.   Serrano's challenge to the District Court's use of the

base offense level of 24 can succeed, therefore, only if Serrano

can show the District Court erred in counting that Article 3.1

conviction. Otherwise, there would be at least two such qualifying

convictions.      We thus now turn to the propriety of the District

Court's finding on that point.

            The   first     thing   to    note   is    that    Article   3.1   is    a

divisible statute. It covers "[a]ny person who employs physical

force or psychological abuse, intimidation or persecution against

the person of [a domestic partner] . . . to cause physical harm to

the person, the property held in esteem by him/her, . . . or to

another's person, or to cause grave emotional harm . . . ."                    P.R.

Laws Ann. tit. 8, § 631 (emphasis added).                The statute thus sets

out multiple constellations of elements in the alternative.                     One

set of elements requires the use or threat of "physical force."

The   others      require     "psychological          abuse,    intimidation        or

persecution."


                                         -13-
          Faced with such a statute, we ordinarily would apply the

modified categorical approach. Using that approach, we first would

try to determine, from the relevant documents, whether Serrano's

prior conviction under Article 3.1 was for an offense predicated on

the "physical force" element or instead for an offense predicated

on the other elements set forth in that statute.       Then, after

having identified the actual offense of conviction, we would

determine whether that offense met the guideline's requirements for

a crime of violence.

          But we are frustrated in doing so here.   Serrano made no

specific challenge to the pre-sentence report's contention that the

list of his prior convictions included two felonies that were for

a crime of violence.   That was so even though that list included a

conviction under Article 3.1 but did not specify further the

particular offense under that law that had resulted in that

conviction.   At sentencing, moreover, the District Court simply

identified as qualifying convictions the one for assault and the

two for domestic violence.   Yet Serrano did not complain that the

District Court, in so finding, did not consult the limited set of

documents from the court of conviction that would have helped it

determine the distinct elements of the offense that provided the

basis for Serrano's actual 2005 conviction under Article 3.1.   In

consequence, we have no such documents to review as part of the

record on appeal.


                                -14-
           As a legal matter, moreover, Serrano's failure to object

in the District Court affects the standard of review.              Rather than

reviewing de novo whether the conviction under Article 3.1 counts

as a conviction for a crime of violence, see 

,

we   may   review     only   for    plain        error,   United   States   v.

Ríos-Hernández, 

, 462 (1st Cir. 2011).                   And that

standard is strict.     Serrano can satisfy it "if, and only if, [he]

succeeds in showing '(1) that an error occurred (2) which was clear

or   obvious   and   which   not   only    (3)    affected   the   defendant's

substantial rights, but also (4) seriously impaired the fairness,

integrity, or public reputation of judicial proceedings.'"              United

States v. Padilla, 

, 218 (1st Cir. 2005) (quoting

United States v. Duarte, 

, 60 (1st Cir. 2001)).

           Of course, if it were clear or obvious that none of

Serrano's prior felony convictions -- save for the 2006 one for

assault -- could qualify as one for a crime of violence, then the

defendant's task on appeal might not be so daunting, despite the

strict standard of review. But because Serrano was convicted under

Article 3.1, and Article 3.1 is a divisible statute, we could come

to that conclusion only if we were confident that none of the

distinct offenses set forth in that law would so qualify.              And, as

we now explain, we are not of that view, given how we interpret one

portion of Article 3.1.




                                    -15-
                                     C.

           The case for concluding that at least one offense under

Article 3.1 qualifies as a crime of violence is strong.            Among the

divisible offenses set forth in that statute is one that covers

"[a]ny person who employs physical force . . . to cause physical

harm" to a protected person.        P.R. Laws Ann. tit. 8, § 631.

           In making physical force an element, the text of Article

3.1   suggests   that   something    more   than   a   mere   non-consensual

touching is required to satisfy that element.            Instead, the text

requires the physical force be intended to "cause physical harm."

The Puerto Rico Supreme Court has also interpreted the physical-

force element of Article 3.1.       And consistent with the text, that

court has construed that element to "prohibit[] . . . physical

abuse," Pueblo v. Ayala García, 

, 213 (2012)

(translation provided by stipulation of parties through letter

under Federal Rule of Appellate Procedure 28(j)), and stated that

"any degree of force is sufficient to configure the offense if

. . . employed with the intention of causing some damage," id.; see

also Pueblo v. Roldán López, 

, 61 (2002).

           Taken together, the text of Article 3.1 and the Puerto

Rico Supreme Court's interpretation of it strongly suggest the

statute's physical-force element involves the kind of violent force

"capable of causing physical pain or injury to another person."




                                    -16-


.5      And that is the kind of force required

by the crime of violence sentencing guidelines' force clause.                  

extent any uncertainty remains, moreover, we do

not believe it is so great as to make it clear or obvious that the

physical-force offense set forth in Article 3.1 could not qualify

as a crime of violence under the guideline.                Yet it is just such a

clear or obvious exclusion from the guideline that Serrano must

demonstrate    given     that   our     review        is    for    plain    error.

            Serrano argues, however, that he still should win because

it is at least possible he was convicted of an offense under

Article 3.1 that does not qualify as a crime of violence.                  And that

is because, he contends, that statute is divisible and the elements

of "psychological abuse, intimidation or persecution" plainly do

not   set   forth   an   offense   that      is   a    crime      of   violence.

            Serrano rests that fall-back contention on more than his

assertion that those particular elements, by their plain terms, do

not require "physical force" or a threat of such force.                    He also

argues those elements establish distinct offenses that are too

unlike the other crimes enumerated in the residual clause of the


      5
       We thus need not address whether the physical-force offense
qualifies as a crime of violence under the guideline's residual
clause, which sweeps in offenses that "involve[] conduct that
presents a serious potential risk of physical injury to another."
U.S.S.G. § 4B1.2(a)(2).     We note that the Supreme Court has
recently asked for briefing on the question whether identical
language in a distinct criminal statute, the Armed Career Criminal
Act, 

. §924(e)(2)(B)(ii), is unconstitutionally vague.
Johnson v. United States, 

(2015).

                                      -17-
crime of violence guideline to be swept up by it.                       Cf. Begay v.

United   States,      

,    142   (2008)      (holding     that    the

enumerated crimes preceding the residual clause "illustrate the

kinds    of   crimes       that    fall    within   the    statute's     scope"     and

"indicate[] that the statute covers only similar crimes"). Serrano

then closes out this argument by contending that, without documents

that show which elements in Article 3.1 supported his actual

conviction under that law, there is no way to know whether that

conviction qualifies as one for a crime of violence.                     And, in the

face of that claimed uncertainty, he argues, it is plain error to

hold that he was convicted of such a qualifying crime.

              The government responds by arguing that uncertainty about

what such documents might show is beside the point. The government

argues    that, in fact, all offenses described in Article 3.1 are

crimes of violence, or, at least, that we should view them as such

on   review    for   plain        error.     And    the   government     bases      that

contention     on    the    residual       clause   of    the   crime   of   violence

guideline, which, the government contends, encompasses all of those

offenses.      Or, at least, the government contends, the residual

clause of the guideline does not clearly or obviously exclude them,

whether they include the physical-force element or not.

              But we do not need to resolve this dispute over how to

characterize all parts of Article 3.1.               Because our review is only

for plain error, it is enough that we have determined that a


                                           -18-
conviction under the physical-force element of Article 3.1 would

likely qualify as a crime of violence.    For as we next explain, our

precedents show that Serrano may not benefit from having left us

completely in the dark (through his failure to object below) about

what the documents relating to the conviction under Article 3.1

would reveal about whether he was convicted of an offense that

contains the physical-force element or instead some other offense

that does not require proof of that element.

                                   D.

           We confronted a situation very much like this in United

States v. Turbides-Leonardo, 

(1st Cir. 2006).         There,

the defendant also challenged his sentence on appeal because it

rested in part on a conviction under a divisible statute, one

portion of which contained elements that qualified for a guideline

enhancement -- there, for drug trafficking -- and another of which

did not.    

     And there, too, the defendant had not

challenged either the pre-sentence report's characterization that

the conviction was for an enhancement-qualifying offense, or the

district   court's   guideline   calculation   that   tracked   the   pre-

sentence report.     As a result, there were no records available on

appeal to show which of the divisible statute's distinct offenses

was in fact the offense of conviction.     

           After finding the defendant's failure to object below, in

context, actually constituted waiver, 

-- a claim that the


                                  -19-
government does not advance here -- we went on to consider in dicta

whether     the   application      of    the   drug-trafficking    guideline

enhancement should be reversed under the plain error standard, 

-40.     And we concluded it should not. 

the

District Court committed no error in accepting the unchallenged

characterization, but that, even if the District Court had erred in

doing so, reversal was still not justified.           

of the defendant's failure to object

below, we explained, "we [we]re left to guess" the "unknown

variable" of "the contents of the record of the prior conviction."

   And because we were left to guess, "there [wa]s no way

for the appellant to show a reasonable probability that he would be

better off from a sentencing standpoint had the district court not

committed the claimed . . . error."             

reason, we

concluded the defendant could not meet the heightened prejudice

showing plain error review requires.           

   relied   on   Turbides-Leonardo's    reasoning   in

holding there to be no prejudice in United States v. Davis, 

(1st Cir. 2012), our last binding precedent on the issue.

In Davis, the defendant challenged his sentence as relying on a

prior conviction under a divisible assault statute, one portion of

which defined a crime of violence and another portion of which did

not.   

      Davis did not object when the prosecutor and the

pre-sentence report characterized his conviction as qualifying as


                                        -20-
a crime of violence, nor did he object when the District Court

characterized the conviction similarly and relied on it in crafting

the sentence.      

    And so we reviewed only for plain

error.

             We held that, whether or not the District Court clearly

erred by not demanding the documents of conviction before making

the crime-of-violence determination, the defendant bore the burden

of showing "a reasonable probability that, but for the error, the

district court would have imposed a different, more favorable

sentence."    

(quoting 

).

We then held, relying expressly on Turbides-Leonardo's reasoning

about the need to show prejudice, that the defendant did not

satisfy that burden because he failed to point to any reason to

conclude that an examination of the documents would indicate the

conviction was for an offense that does not qualify as a crime of

violence.    

like in Davis, the District Court had before

it a pre-sentence report that claimed the defendant had a second

prior conviction that qualified for the guideline enhancement. And

yet, again, like in Davis, the defendant did not contest that

representation,    even   though   the    defendant   informed   the   judge

through counsel that he had reviewed the pre-sentence report

containing that information.




                                   -21-
             Indeed, although the defendant made a general objection

to the probation office regarding the total offense level used in

the first version of the pre-sentence report, the record does not

indicate that Serrano raised a more specific objection to the

probation office regarding the base offense level and the number of

his prior convictions for a crime of violence.             And, the record

further shows, he failed to do so even after the office clearly

explained its view that Serrano had two such prior convictions.

             Nor   did   the   defendant    raise   an   objection   in   his

sentencing memorandum, or inform the District Court at sentencing

that it believed it had erred in concluding -- as it plainly stated

in announcing the sentence --          that, in addition to the 2006

conviction for assault, there was another qualifying conviction

that was for domestic violence.            The District Court thus had no

Shepard documents before it -- nor any request that it obtain and

review such documents -- that might cast doubt on either the pre-

sentence report's assertion that the enhancement applied or on the

defendant's apparent agreement with that assertion.           Accordingly,

we have no such Shepard documents before us now.              And thus, as

Davis   --    by   incorporating    Turbides-Leonardo's      reasoning     --

instructs,     we have no basis for concluding it is reasonably

probable that those documents would show Serrano was convicted of

an offense under Article 3.1 that would not qualify as a crime of

violence.


                                    -22-
           In fact, even now, on appeal, Serrano still does not

assert he was not convicted under Article 3.1 of the offense

involving physical force, nor does he request to supplement the

record to include the appropriate documents of conviction on the

ground that they would redound to his benefit.          See United States

v.   Zubia-Torres,    

,   1209   n.3   (10th   Cir.   2008)

(declining to consider "the effect if counsel had proffered the

relevant documents on appeal"). He contends only that it cannot be

certain on this record whether he was so convicted and that, in any

event, the "physical force" offense clearly or obviously does not

qualify -- a contention we have already rejected.

           Therefore, as in Turbides-Leonardo and Davis, we conclude

Serrano has not shown the necessary prejudice, even assuming the

District Court erred in not independently seeking out the records

of conviction.6      This conclusion comports with the decisions of


      6
        Because we rely on the defendant's failure to show the
necessary prejudice in this case, we need not address whether it
was clear and obvious error for the District Court to fail sua
sponte to demand and evaluate documents relating to the conviction.
Other circuits have addressed this issue. Compare United States v.
Aviles-Solarzano, 

, 475 (7th Cir. 2010) (characterizing
lack of objection as factual stipulation, and finding no error),
with, e.g., United States v. Castillo-Marin, 

, 921 (9th
Cir. 2012) (finding clear and obvious error). We have held that a
failure to demand and evaluate such documents was not clear and
obvious error where the defendant not only failed to object but
also "apparent[ly] acquiesce[d]" in his sentencing memorandum "to
the characterization of the prior convictions as crimes of
violence" by stating that he "technically qualifies" for the
enhancement. 

. But we held that it
was clear and obvious error in the circumstances addressed by
United States v. Torres-Rosario, 

(1st Cir. 2011), and

                                   -23-
several   sister   circuits   in   similar   plain-error   cases.   See

; United States v. Williams, 

, 966-67 (D.C. Cir. 2004); United States v. Ransom, 502 F.

App'x 196, 198-201 (3d Cir. 2012) (unpublished).      And while we are

aware that other circuits have vacated sentences and remanded after

finding plain error in arguably analogous circumstances, they did

not, in so doing, address the lack-of-prejudice argument that the

other circuits just mentioned have relied upon and that Davis

requires us to find determinative here.          See United States v.

Reyes, 

, 460 (2nd Cir. 2012) (concluding, without

explanation, that the district court's failure to sua sponte

investigate the documents of conviction led to an erroneously

elevated offense level); United States v. Castillo-Marin, 

, 927 (9th Cir. 2012) (same); United States v. Pearson, 

, 1186 (8th Cir. 2009) (same), partially overruled on other

grounds by United States v. Tucker, 

, 1184 (8th Cir.

2014); United States v. Bonilla-Mungia, 

, 321 (5th Cir.

2005) (vacating and remanding without discussing prejudice).

           We do not say, however, that there are no circumstances

in which reversal in a related case, involving different facts,


we came to a similar conclusion in dicta in our recent opinion in
United States v. Ramos-González, 

, 507 (1st Cir. 2015),
on which Serrano relies. We note that we also suggested in Ramos
that we would have found prejudice to the defendant, but in doing
so we did not address the contrary holding on that point of Davis
(based on the reasoning of Turbides-Leonardo), 

we
have explained, controls this case.

                                   -24-
might be warranted.       In United States v. Torres-Rosario, 

  (1st    Cir.    2011),    we   held   the     District    Court    committed

prejudicial plain error in characterizing the conviction at issue

in that case as a crime of violence, 

               But there, under

First Circuit precedent, binding at the time of sentencing, it was

clear from the charging documents in the record that the conviction

qualified categorically as a crime of violence.                

    The

defendant thus understandably did not contest the characterization

or assert that the other documents of conviction would be relevant

to whether the conviction was in fact qualifying, and indeed

stipulated that his convictions qualified.                 

             By the time of the appeal, however, the First Circuit had

changed course in response to a recent case from the Supreme Court.

We had made clear that the type of conviction at issue did not

necessarily qualify categorically as a crime of violence and,

therefore, that further inquiry into the documents of conviction

under the modified categorical approach would be appropriate.                  

     For that reason, the un-objected-to characterization of

the conviction in Torres-Rosario could not have been understood as

an unchallenged agreement to a factual characterization of the

conviction.

             Here, by contrast, as in Turbides-Leonardo, no First

Circuit precedent, later overruled, established at the time of

sentencing     that    the     conviction     for    the    underlying     offense


                                       -25-
categorically qualified as a crime of violence.                         And so the

defendant's failure to contest the pre-sentence report's and the

District Court's characterization of those prior convictions is, as

Davis held in applying Turbides-Leonardo, key to our assessment

that he has not met his burden of showing prejudice.                       And while

Davis is itself a case with facts like Torres-Rosario, that does

not make its express adoption of Turbides-Leonardo's prejudice

analysis any less controlling in a case like this one, which

mirrors the facts in Turbides-Leonardo rather the facts in Torres-

Rosario.     We thus do not address how Davis and Torres-Rosario's

analysis of the prejudice issue should be reconciled in a case

presenting the distinct facts presented in those cases.

                                        III.

            Under    the     Sentencing       Guidelines,    the    offense       level

increases by four points if the firearm involved in a felon-in-

possession       conviction    "had    an   altered    or   obliterated          serial

number."     U.S.S.G. § 2K2.1(b)(4)(B).               Serrano's pistol had an

obliterated serial number on the frame and an unaltered serial

number on the slide.           The District Court therefore applied the

four-point serial-number enhancement.

            Serrano argues, however, that the District Court erred

because    the    serial     number,   though     obliterated      in   one      place,

remained unaltered elsewhere on the gun.                   He contends that the

guideline    could     not     have    been     intended    to     apply    in     such


                                        -26-
circumstance because the serial number itself remains perfectly

visible, albeit in only one place rather than two.

           Whether Guideline § 2K2.1(b)(4)(B)'s four-point serial-

number enhancement may apply in this type of case is a question of

law (and, apparently, a question of first impression).       Because

Serrano properly preserved this argument below, our review is de

novo.   See United States v. Maldonado, 

, 17 n.1 (1st

Cir. 2010) ("Abstract legal issues under the          guidelines are

reviewed de novo . . . .").

           Like the District Court, we conclude the enhancement does

apply in Serrano's case.   The text of the guideline requires only

"an     altered   or   obliterated      serial   number,"    U.S.S.G.

§ 2K2.1(b)(4)(B) (emphasis added).      The guideline's text does not

require that all of the gun's serial numbers be so affected.      And

here, the complete defacement of the serial number on the frame of

the firearm resulted in the required obliteration.

           Moreover, this plain reading of the text -- that the

obliteration of "a[]" serial number is enough -- accords with the

intent of Guideline § 2K2.1(b)(4), which is "to 'discourag[e] the

use of untraceable weaponry.'"    United States v. Carter, 

, 914 (9th Cir. 2005) (alteration in original) (quoting United

States v. Seesing, 

, 460 (9th Cir. 2001)). Applying an

enhancement for firearms that have a single totally obscured serial

number may serve as a deterrent to tampering, even when incomplete.


                                 -27-
And, relatedly, the single-obliteration rule could facilitate

tracking each component that bears a serial number, given that

various parts of firearms may be severable.

          And precedent is not to the contrary.          We have held the

mere alteration of a serial number violates 18 U.S.C. § 922(k), a

related criminal statute, without regard to whether such alteration

is severe enough to prevent that same serial number from being

read, United States v. Adams, 

, 34 (1st Cir. 2002); see

also 

(applying Adams to interpret

Guideline § 2K2.1(b)(4)(B)). So, too, we conclude the text of this

guideline is best construed -- consistent with the plain meaning of

its words -- to trigger the enhancement when the serial number on

the frame of a firearm is obliterated even if other serial numbers

on the firearm, like the one left intact on the slide of this

weapon, are unaltered.7   We thus do not believe the District Court

erred in applying the four-point enhancement.

                                   IV.

          For   these   reasons,    we    affirm   the   District   Court's

sentence against the challenges raised in this appeal.

                   -Concurring Opinion Follows-



     7
          We do not need to reach the further issue whether the
guideline would apply if the serial number on the frame were
unaltered but a serial number on the slide or other part of the
firearm were altered or obliterated.      See United States v.
Romero-Martinez, 

(9th Cir. 2006) (holding the
guideline applicable in such a case).

                                   -28-
              LIPEZ, Circuit Judge, concurring.             A defendant whose

sentence is enhanced because of violent crimes he committed in the

past will face substantially more time in prison than someone

without   a    record   of   violence.      Although    I    do   not   question

sentencing     enhancements    for   defendants    with     violent     criminal

histories, we must ensure that aggravated penalties are imposed

only when the criminal histories justify them.                Here, appellant

challenges the district court's unsupported assumption that his

conviction under a "divisible" statute was in fact for a crime of

violence.       I reluctantly agree with my colleagues that First

Circuit   precedent     requires     us   to   reject   appellant's       claim.

However, our case law on how to evaluate plain error in this

context is inconsistent, and it cannot be reconciled with the

Supreme Court's decision in Shepard v. United States, 

(2005).   I therefore urge our court to rehear this case en banc so

that we may closely examine, and fairly resolve, an important and

complex question of law: how does the government's burden to

establish that a conviction under a divisible statute qualifies as

a predicate offense intersect with a defendant's burden to show

plain error?

              Under the analysis described in the majority opinion,

appellant can satisfy the prejudice prong of the plain error test

only if he proves that, but for the sentencing court's improper

reliance on his Article 3.1 conviction, it is reasonably probable


                                     -29-
that he would have received a lesser sentence.                   As a practical

matter, that approach switches to defendants the obligation the

Supreme Court imposed on the government to produce specific court

records    proving   that   a   conviction      under    a    divisible    statute

qualifies as a predicate offense.               In so doing, the approach

creates a real risk of longer prison terms than are justified by

defendants' criminal histories. As other circuits have recognized,

however, that potential harm can be easily avoided, with minimal

burden on the sentencing court.         When the court erroneously relies

on a conviction whose character cannot be determined without

Shepard-approved     documents,    the       defendant's      sentence     must   be

vacated and the case remanded for resentencing.                  The government

will then ordinarily have the opportunity to substantiate that the

conviction was for an offense that qualifies as a predicate for

enhancement.      If the government cannot do so, the enhancement is

impermissible.

            As I explain below, this modest relief follows as a

matter of logic and fairness from correct application of the plain

error test in this context.       Indeed, with a full understanding of

the underlying principles, one can only conclude that the prejudice

analysis articulated in our precedent -- requiring the defendant to

disprove    his   eligibility     for    a    sentence       enhancement    --    is

misguided. Our court should convene en banc to remedy this serious

problem.


                                    -30-
                                     I.

A. Legal Background

          As my colleagues explain well, when a court seeks to

enhance a defendant's sentence based on a prior conviction under a

"divisible"   statute   --   i.e.,   where   the   statute   criminalizes

different types of conduct, only some of which may support the

enhancement -- the court applies the so-called modified categorical

approach to determine which version of the crime underlies the

defendant's conviction.      Descamps v. United States, 

, 2283-84 (2013); see also United States v. Ramos-González, 

, 505 (1st Cir. 2015) (describing a "divisible statute" as

one that "sets forth one or more elements of a particular offense

in the alternative" (quoting United States v. Fish, 

, 6

(1st Cir. 2014)).     Frequently, as in this case, the enhancement

depends on whether the challenged prior conviction was for a "crime

of violence."8   See, e.g., 

.        If

a statute criminalizes both violent and non-violent conduct, "the

sentencing court is permitted to consult a limited set of 'approved

records' to determine which . . . provided the basis for the

conviction." 

(quoting United States v. Carter, 

       An offense qualifies as a crime of violence if it is
punishable by more than one year of imprisonment and either "(1)
has as an element the use, attempted use, or threatened use of
physical force against the person of another," or (2) is one of
several enumerated crimes not relevant here, "or otherwise involves
conduct that presents a serious potential risk of physical injury
to another." U.S.S.G. § 4B1.2(a).

                                 -31-
8, 19 (1st Cir. 2014)).        The permissible records consist primarily

of   charging   documents,      plea   agreements,   transcripts      of   plea

colloquies, jury instructions, and verdict forms.              Id.; see also

(describing the acceptable records, often

described as "Shepard materials").            If the records show that the

defendant was not convicted of a crime containing the requisite

elements of violence -- or if the records do not reveal the nature

of the crime -- the conviction may not be used to enhance his

current federal sentence.        See United States v. Dávila-Félix, 

, 57 (1st Cir. 2011).

            At sentencing, the burden to produce the documents that

reveal (or not) the nature of the proffered conviction is on the

government.     

("The Government bears

the burden of establishing that a prior conviction qualifies as a

predicate offense for sentencing enhancement purposes.").              Hence,

if   the   government   does    not    demonstrate   that    the   defendant's

conviction was for a variant of the crime that satisfies the crime-

of-violence definition, it is error for the court to treat that

conviction as a predicate for sentencing enhancement purposes.

This is so whether the documents show the crime to be of the non-

violent type or if the documents do not reveal the particular

version of the crime underlying the conviction.             See United States

v. Davis, 

, 8 (1st Cir. 2012) ("If, after examination of

these permissible documents, 'it is impossible to tell whether the


                                       -32-
defendant was convicted of a violent or non-violent offense,' the

conviction may not serve as a predicate offense." (quoting United

States v. Holloway, 

, 257 (1st Cir. 2011)).

          The complexity arises if the defendant fails to challenge

the sentencing court's reliance on such a conviction, and raises an

objection for the first time on appeal.   We treat such a claim as

forfeited and give it only plain error review.9         Under that

standard, the defendant "bear[s] the 'heavy burden' of showing that

the error was clear or obvious, and that it both affected his

substantial rights and 'seriously impaired the fairness, integrity,

or public reputation of judicial proceedings.'"    

(quoting United States v. Ramos-Mejía, 

,

14 (1st Cir. 2013)).

          To perform this inquiry, we need to identify the "error"

before we can determine if it is clear or obvious, and prejudicial.

Focusing on the Puerto Rico statute under which the defendant was

convicted, my colleagues explain that we may find plain error only



     9
       Although the terms "waiver" and "forfeiture" are sometimes
used interchangeably, "[w]hether an objection has been waived or
simply forfeited affects the scope of our appellate review."
United States v. Gaffney-Kessell, 

, 100 (1st Cir. 2014).
Waiver occurs when a litigant intentionally relinquishes or
abandons a known right, and we ordinarily will not consider a
waived issue on appeal. 

States v. Olano, 

, 733 (1993)). Forfeiture refers to "a 'failure to make
the timely assertion of a right.'" 

507 U.S. at
733). "A forfeited issue still may be reviewed on appeal, albeit
for plain error."      

is important and
consequential in cases like the one before us.

                               -33-
if we are "confident that none of the distinct offenses set forth

in that law" would qualify as a crime of violence.               Slip op. at 16.

Otherwise,    they   say,     an   error    in   using   the   conviction   as   a

predicate for enhancement would not be clear or obvious. Moreover,

drawing on our precedents, they conclude that the defendant cannot

satisfy the prejudice prong of the plain error inquiry unless he

shows "'a reasonable probability that, but for the error, the

district court would have imposed a different, more favorable

sentence.'"    Slip op. at 21 (quoting 

, which

in turn quoted United States v. Turbides-Leonardo, 

, 39

(1st Cir. 2006)).       To accomplish this showing of prejudice, the

defendant, in effect, is required to produce Shepard materials

revealing that his conviction was for a non-violent offense.

             The animating principle of the modified categorical

approach, however, is that enhanced sentencing is improper unless

the   government     proves    that   the    defendant's       criminal   history

justifies    such    severe    punishment.         Error   occurs,   therefore,

whenever a sentencing court increases a term of imprisonment based

on a predicate conviction under a divisible statute in the absence

of Shepard-approved proof that the conviction was for a qualifying

variant of the crime.         For that reason, the defendant's burden in

the trial court is simply to note the absence of proof, not to

proffer the supporting documents to disprove his eligibility for an

enhancement.     Under the approach my colleagues draw from prior


                                      -34-
cases, Serrano's failure to make that simple objection to the lack

of proof transferred the duty of production to him on plain error

review.10

            Although my colleagues understandably follow a path set

out in prior cases, this dramatic shift of responsibility is unfair

and wrong.      I therefore first review why I view our precedent as

flawed    and   incompatible   with   Supreme   Court   precedent   before

elaborating on what I believe is the proper analysis.

B. The Varying Paths of our Prior Cases

            Our cases do not present a uniform approach for analyzing

plain error in the context of a claim that the district court

improperly lengthened a sentence based on the defendant's prior

conviction under a divisible statute.       In some instances, we have

held the government accountable for the absence of evidence in the

record.     See, e.g., 

(vacating

sentence that included career offender status because the records

submitted by the government did not show the nature of defendant's

conviction under a divisible statute); 

(concluding that, "on the record before us, the Government has not

met its burden of proving that [defendant's] prior drug conviction

qualified as a career offender predicate"); United States v.

Torres-Rosario, 

, 117 (1st Cir. 2011) (noting that,


     10
       Likewise, even if a defendant insists that the crime of
conviction is not a crime of violence, he does not have to prove
that assertion.

                                  -35-
"[o]n remand, the government remains entitled to establish the

[basis for the sentencing enhancement] by showing that one of the

assault and battery convictions was a crime of violence" (citation

omitted)). In the latter two cases, however, the courts identified

reasons why the defendants understandably failed to make an earlier

challenge to the depiction of their convictions as qualifying

predicates, thereby articulating justifications for remanding the

case for resentencing notwithstanding the defendant's heavy burden

on plain error review.11   In Ramos-González, the government already

had had multiple opportunities to prove career-offender status, and

the panel declined to give the government a third 

.

          In other cases involving divisible statutes, panels of

this court have held the defendants accountable for the absence of

supporting documents in the record despite the government's burden

to produce such records.      See, e.g., 

;

.    In these cases, the panels

bypassed explicit identification of the error and -- ostensibly

addressing the prejudice prong of the plain error standard --

articulated the requirement relied on by my colleagues: a defendant


     11
       In Dávila-Félix, the court noted that the drug convictions
at issue "were only briefly referenced and were not discussed or
relied upon at 

. In Torres-Rosario,
the panel excused a concession that the defendant fell within the
armed career criminal statute (an arguable waiver) because of a
change in First Circuit law prompted by new Supreme Court
precedent. 

.

                                 -36-
must show that, absent the error, he probably would have received

a shorter sentence. 

; 

.

          As I explain below, the failure to confront the nature of

the error is a threshold flaw in the Turbides-Leonardo and Davis

assessments   of   plain   error,    and     the   mistake   results   in   a

misdirected   prejudice analysis.      As my colleagues recognize, the

plain error analysis in Turbides-Leonardo was dicta, given the

panel's statement that, "[a]ll things considered, we think that

what transpired here amounted to 

.12      In

Davis, the panel followed the Turbides-Leonardo dicta without

analyzing its legal foundation, perhaps because the defendant's

conduct there manifested waiver.13         Davis complained that he should

not be sentenced as a career offender, but he never argued that


     12
       In my view, the circumstances described in Turbides-Leonardo
do not show waiver. Waiver should be reserved for cases in which
the defendant explicitly agrees that particular listed crimes
qualify as predicates, and it should not be inferred from silence.
See 

("At least where a party makes
an explicit and specific concession, practical reasons favor
holding a party to such a concession . . . .").        In Turbides-
Leonardo, the defendant simply failed to object, both to the
Presentence Investigation Report ("PSR") and at sentencing, which
is forfeiture.   

.     Nonetheless, the decision
incorporates an assumption that waiver occurred, and I will do
likewise. In the case now before us, Serrano did object to the
PSR's guidelines calculation, albeit on other grounds.          The
government does not argue waiver, and I agree that Serrano's
failure to object specifically on the predicate-crime issue is
properly characterized as forfeiture.
     13
       Indeed, the scenario in Davis is more aptly labeled a waiver
than were the circumstances described in Turbides-Leonardo.

                                    -37-
career-offender status was improper because the district court

failed   to    determine   the   nature   of   the   pertinent   predicate

conviction.     

n.2, 7, 10 n.7.      In fact, appellate

counsel twice sought to withdraw on the ground that he "'could not

discern a non-frivolous basis for appeal.'"          

n.2 (quoting

counsel's brief).      The panel refused those requests and directed

counsel to address the plain error standard. Counsel, however, did

not submit briefing on plain error and, "when questioned at oral

argument regarding any potential prejudice to Davis based on the

district court's failure to undertake the categorical approach or

to examine the character of Davis's 2006 assault and battery

conviction, Davis's counsel could not point to any."             

n.7.

              In these circumstances, I can understand how the Davis

panel came to rely on the Turbides-Leonardo approach to plain error

without closely examining it or explicitly acknowledging it as

dicta.   Treating Davis's claim as forfeited rather than waived was

generous and, given that Davis did not raise the district court's

failure to apply the modified categorical approach even on appeal,

the panel had no reason to probe deeply into the Turbides-Leonardo

articulation of the inquiry.      Here, by contrast, Serrano develops

his claim that the district court erred by counting his domestic

violence offense as a predicate crime of violence, asserting, inter

alia, that some crimes under Article 3.1 "clearly do not involve


                                   -38-
the use of violent force."    Br. at 23.      Nonetheless, because Davis

applies the plain error test to a scenario it labels as forfeiture,

it appears to be binding precedent on the application of the plain

error test where, as here, there are no distinguishing facts like

those in Ramos-González, Dávila-Félix, or Torres-Rosario.

          The fact remains, however, that our cases fail to deal

consistently with the government's initial burden of proof in the

plain error context.   Where the government was required to retain

the burden to prove the nature of the defendant's conviction, the

courts relied on particular circumstances -- a change in the law,

the convictions' non-essential role in the prior sentencing, or the

government's multiple prior attempts -- to explain the defendants'

default or find the burden unmet.         In the two instances where the

burden was switched from the government to the defendant, the

courts   dealt   explicitly   or    de     facto   with   an   intentional

relinquishment of the defendant's rights -- a waiver -- and avoided

the question of what error the court committed.                We have not

examined how, or if, these cases may be reconciled with each other

and whether they achieve the objectives of the modified categorical

approach. Furthermore, the uneven treatment within our own circuit

is reflected in a conflict among the circuits.            Compare, e.g.,

United States v. Dantzler, 

, 149 (2d Cir. 2014) ("The

absence of an objection will not relieve the Government of its

burden of proving through Taylor- and Shepard-approved sources that


                                   -39-
the ACCA enhancement applies."), with, e.g., United States v.

Zubia-Torres, 

, 1209 (10th Cir. 2008) ("By failing to

present any evidence that relevant documents would indicate his

conviction was not for [a qualifying predicate offense], the

defendant has failed to meet his burden under the third prong of

plain error review.").

            In sum, we lack a thoughtful, uniform analysis for

assessing plain error when a defendant claims that his sentencing

enhancement was improperly based on an unexamined conviction under

a   divisible   statute.   Our   court,   en    banc,   should   take   the

opportunity to develop such an analysis in this case.

C. The Correct Approach

            To properly conduct the plain error inquiry, a court must

have a correct understanding of the error at issue.         As described

above, some of our cases have sidestepped the question of error to

focus on the question of prejudice.       In so doing, however, those

courts performed an analysis premised on a misidentification of the

error, which leads them to cast aside the government's burden of

proving the basis for an enhancement.          In Turbides-Leonardo and

Davis, the panels focus on the enhanced sentence, and consequently

evaluate prejudice by asking the usual question we ask when

sentences are reviewed for plain error: is it reasonably probable

that, but for the error, the defendant would have received a lower

sentence?    The length of the sentence -- though ultimately our


                                 -40-
concern -- is not the "plain" error.         Because the government

initially bears the burden to prove that a conviction represents a

crime of violence, 

, the error occurs

when the district court enhances a sentence based on a prior

conviction under a divisible statute without first confirming that

the conviction qualifies as a predicate offense. That confirmation

may be achieved in various ways: through documentary evidence

(i.e., the Shepard materials), by concession of the defendant, or

by means of an interpretation of the predicate criminal statute --

i.e., a legal ruling by the court -- that every variant of the

offense qualifies as a crime of violence.

          Here, where the statute on its face appears to encompass

alternatives that neither involve physical force against a person

nor present a "serious potential risk of physical injury to

another," U.S.S.G. § 4B1.2(a),14 the court erred by using the

conviction to enhance Serrano's sentence without demanding proof

from the government that the defendant's conviction was for a

violent version of the divisible crime.      It is possible that the

enhancement is also erroneous because the conviction at issue was

not, in fact, a crime of violence.    But to find that the sentencing



     14
       Article 3.1 applies to "[a]ny person who employs physical
force or psychological abuse, intimidation or persecution against
the person of [a domestic partner] . . . to cause physical harm to
the person, the property held in esteem by him/her, . . . or to
another's person, or to cause grave emotional harm . . . ." P.R.
Laws Ann. tit. 8, § 631.

                               -41-
judge erred in applying the modified categorical approach, an

appellate court need not reach the nature of the conviction. Error

has   occurred     when    the   court   relies   on   a   conviction   under   a

divisible statute without confirming, through approved sources

provided by the government, that the conviction represents a crime

of violence.15

            The failure to recognize this error is what led the

Turbides-Leonardo panel astray.             Its approach looks beyond the

district court's erroneous reliance on an unelaborated conviction

under a divisible statute and asks whether the defendant has shown

that the proper analysis would have revealed that the conviction

was erroneously used as a predicate for enhancement.               Even if the

district court had performed the proper analysis, however --

involving the scrutiny of Shepard-approved documents -- the inquiry

may   not   have    shed    light   on    the   predicate   conviction.     The

government may not have been able to produce appropriate records of

the targeted conviction -- the documents may be inaccessible or no

longer exist, meaning that the conviction could not be used to


      15
        I address in this concurrence only the treatment of
predicate convictions under a divisible statute, where the statute
on its face provides notice to the government and the court that a
conviction is unusable as a predicate offense without further
inquiry under the modified categorical approach. I therefore do
not consider the nature of plain error review for challenges to
predicate convictions under "'indivisible' statute[s]." 

; 

(holding that "sentencing courts
may not apply the modified categorical approach when the crime of
which the defendant was convicted has a single, indivisible set of
elements").

                                         -42-
enhance the defendant's sentence.          Hence, by focusing on the

possibility that the defendant was convicted of a qualifying crime,

and requiring him to prove that he was not, we unfairly leap over

the   threshold   analytical   error,    i.e.,   the   sentencing   court's

failure to require the government to establish the nature of the

conviction through approved sources.

           If that error were properly acknowledged, the plain error

analysis here would unfold unequivocally in the defendant's favor.

Given the broad language of Article 3.1, and the dearth of evidence

indicating whether the defendant was convicted of a crime of

violence, the court's error in relying on the unexamined conviction

was sufficiently "plain" to satisfy the second prong.          The gap in

the record should have been obvious to the court.           The remaining

two elements are equally straightforward.        A defendant inescapably

suffers prejudice when he receives an extended term of imprisonment

without the evidentiary support necessary to justify it,16 and an



      16
        In the career offender context, the error technically
results in an elevated base offense level, which can be presumed to
lead the district court to impose a longer sentence than would
otherwise apply. See 

(noting
that a lower Guidelines sentencing range "presumably [will result
in] a more lenient sentence"). In the context of the Armed Career
Criminal Act ("ACCA"), the erroneous reliance on predicate
convictions may trigger improper mandatory minimum sentences. See,
e.g., 

(noting that the ACCA mandates a
minimum 15-year sentence after three convictions for serious drug
offenses or violent felonies). We have long treated precedent on
the ACCA and the Guidelines career offender enhancement
interchangeably with respect to the modified categorical approach.

n.24.

                                  -43-
unsupported, prolonged incarceration must be deemed a miscarriage

of justice.    See 

& n.29; Torres-

.17

            Admittedly, this plain error analysis has the feel of

allowing the defendant to escape with little disadvantage from his

failure to make a timely objection.    All four prongs of the plain

error inquiry effectively turn on the finding that the error was

plain, and the error will almost always be plain when there are no

supporting documents in the record.      Importantly, however, the

typical remedy for a finding of prejudicial plain error in this

context is simply a remand for development of the sentencing

record.    In many instances, the government on remand will be able

to produce the necessary documents to substantiate the qualifying

predicate offense, and the defendant's "victory" will be short-

lived.    This is the approach taken by a number of   circuits.   See,

e.g., United States v. Reyes, 

, 459-60 (2d Cir. 2012)

(per curiam) (finding plain error requiring remand where the

district court relies on the PSR to characterize an offense as a

"crime of violence," "even where the defendant does not object to

the PSR's description"); United States v. Castillo-Marin, 

, 919, 927 (9th Cir. 2012) (same); United States v. Boykin, 669


     17
        My discussion presumes that the defendant's PSR does not
list other predicates that categorically qualify as crimes of
violence and could be substituted for the one on which the district
court erroneously relied. The prejudice assessment obviously would
be different if that were the situation.

                                -44-
F.3d 467, 469-72 (4th Cir. 2012) (finding plain error and remanding

for resentencing where the district court relied on the PSR to

conclude that the defendant had the requisite number of violent

felonies for ACCA enhancement); United States v. McCann, 

, 502 (5th Cir. 2010) ("When a court . . . relies on the PSR

alone [to characterize an offense as a crime of violence], it makes

an error that is clear and obvious.").

             Moreover, we must acknowledge the potentially severe

consequences of using prior convictions improperly -- substantially

prolonged terms of incarceration.18        Undoubtedly, that harsh impact

underlies the Supreme Court's carefully circumscribed list of

acceptable    records   for   confirming    that   a   conviction   under   a

divisible statute may be used to enhance a sentence.           At the same

time, it is an unfortunate reality that many claims such as

Serrano's come to us on plain error review.            Criminal defendants

often must rely on court-appointed counsel who, faced with a myriad

of trial and sentencing issues, predictably overlook some of them.


     18
        For example, in Shepard, which involved the ACCA, the
government stated that Shepard's prior convictions "raised his
sentencing range from between 30 and 37 months (under the United
States Sentencing Guidelines) to the 15-year minimum required by
[the 

. In United States v. Martin, 

(1st Cir. 2014), we described as "significant" the
difference in sentence between career offender status and non-
career offender status: a career offender range of 188 to 235
months compared with an otherwise applicable sentencing range of 27
to 33 months.    

    See also, e.g., United States v.
Castillo-Marin, 

, 927 (9th Cir. 2012) (comparing
Guidelines range of 46-57 months with enhancement based on crime of
violence to range of 0-6 months absent the enhancement).

                                   -45-
The extremely high hurdle to post-conviction relief based on

ineffective assistance of counsel means that such a remedy is

uncertain at best.

           In short, there is simply no reason to apply plain error

in a way that will leave intact lengthy, possibly unjustified terms

of   imprisonment    when     the   cost    of   ensuring    fairness    --   a

resentencing    proceeding     --   is     minimal.     We   should     not   be

uncomfortable    with    an   "easy"     showing   of   plain   error,    even

recognizing the high bar that the plain error standard ordinarily

represents.     Indeed, the fourth prong of the plain error test

requires us to consider "'the fairness, integrity, or public

reputation of judicial proceedings.'"            United States v. Mercado,

, 536 (1st Cir. 2015) (quoting United States v. Duarte,

, 60 (1st Cir. 2001)).            The plain error approach we

apply in this case is incompatible with those concerns.

D.   The Role of the PSR

           The mistaken approach to plain error adopted in Turbides-

Leonardo reflects the confusion in our law about when it is

appropriate to rely on an unobjected-to PSR to prove a defendant's

criminal history.       Courts may accept the PSR's representation of

the existence of a prior conviction in the absence of objection.

See, e.g., United States v. Jimenez, 

, 7 (1st Cir. 2007)

(stating that, where an offense listed in a presentence report "is

not disputed before the sentencing court, the report itself is


                                     -46-
competent evidence of the fact stated and, thus, is sufficient

proof of that fact"); United States v. Brown, 

, 74 (1st

Cir.   2007)   (describing   the   government's   burden   of   proving   a

predicate conviction for sentencing purposes as "modest," and

noting that it can be satisfied by, inter alia, "introducing a

certified copy of the judgment, or by a statement in the PSR").

           However, courts are not permitted to rely on the PSR to

establish the character of a conviction under a divisible statute.

A decision to accept the PSR as adequate evidence of the nature of

a defendant's prior crimes would conflict with the Supreme Court's

directive that the particular offense committed in violation of a

divisible statute be determined through examination of Shepard-

approved documents. Indeed, police reports are a typical source of

the facts reported in a PSR, see, e.g., 

(noting that the PSR's summary of a prior crime was based on a

police report), and police reports are expressly excluded from the

list of approved documents, see, e.g., 

(noting that we "may not rely on the police reports related to

the earlier conviction" (quoting 

(citing

))). Although the PSR will commonly include

the details of the defendant's criminal conduct, it will not

necessarily reveal the pertinent information for the modified

categorical approach, i.e., the specific elements of the crime

underlying the listed convictions.        See, e.g.,   Descamps, 133 S.


                                   -47-
Ct. at 2283 ("The key [in determining whether a prior conviction

can serve as an ACCA predicate] . . . is elements, not facts.");

(noting that a defendant may have pled guilty to a less

serious version of the crime than reflected in factual statements

"found in the old record").

           Thus, although our cases unequivocally allow a sentencing

court to rely on the PSR to confirm the existence or validity of

convictions in the absence of an objection, other cases properly

recognize that such deference cannot extend to the question whether

convictions   under    a      divisible     statute   represent      qualifying

predicates for sentencing enhancements.           See, e.g., 

(rejecting government's reliance "primarily upon

the facts as recounted in the presentence investigation report,"

despite the defendant's failure to object to the PSR's analysis);

(stating that sufficient proof of the two

prior convictions "does not necessarily end our inquiry" because

"[i]n some circumstances, the question would remain whether the

underlying offenses qualify as controlled substance offenses within

the meaning of the applicable sentencing guideline").

           Yet, in Turbides-Leonardo, the panel cited a single

Eighth Circuit case for the proposition that a PSR "may be a

permissible source of information about a prior conviction for

sentence enhancement purposes" to bolster its conclusion that the

district   court      acted     "reasonabl[y]"        in   relying     on   the


                                     -48-
uncontroverted PSR to enhance the defendant's sentence based on a

conviction under a divisible 

(citing

United States v. Arrieta-Buendia, 

, 955-56 (8th Cir.

2004)).     In the Eighth Circuit case, however, the defendant had

admitted his conviction for a type of crime that qualifies as a

predicate offense.         See 

(stating

that the defendant "told the district court he was not guilty of

the California felony of transporting methamphetamine, but was

forced to plead guilty to that crime").                      Arrieta-Buendia is not

only an out-of-circuit precedent, but it also is inapt where, as

here,   the    PSR   does       not   reveal    whether      a   conviction   under    a

divisible     statute      is    an   eligible     predicate       offense    and   the

defendant has not waived or conceded the point.

              To   some    extent,     the     panel    in   Davis   recognized     the

difference between using a PSR to prove the fact of a conviction

under a divisible statute and relying on the report to establish

the specific elements of the crime underlying that conviction.                        At

issue in Davis was whether a conviction for assault and battery was

a predicate offense for career offender 

.

The panel noted that the only evidence in the record indicating the

violent nature of the offense was in the PSR, with details drawn

from police reports.            

8-9.         The defendant, however, did

not object to the PSR's characterization of the offense as a crime

of   violence,       and        he    did    not   contest        the     government's


                                            -49-
characterization of him as a career offender at the sentencing

hearing.   

.     On appeal, as discussed above, the panel found

that the defendant had failed to satisfy the prejudice prong of the

plain error inquiry: "[Defendant] has made no argument that the

assault and battery was anything other than the harmful type, doing

nothing, even on appeal, to question the description provided in

the PSR or to argue that appropriate Shepard materials would prove

that he committed a non-harmful battery."       

.

           The   Davis    panel,   however,   directly   confronted   the

adequacy of the PSR to show the requisite violent conduct.             It

first quoted the assertion in Torres-Rosario that "'treating a

Massachusetts assault and battery conviction as a [career offender]

predicate, without further evidence of violence, is now plain

error.'"    

(quoting 

)

(alteration and emphasis in Davis).       The Davis panel then went on

to speculate that "the description in the PSR might constitute such

further evidence," and, for that reason, "this case does not neatly

fall within the plain error standards we set in Torres-Rosario."

immediately following footnote, the panel observed that

"[w]e have never squarely addressed whether reliance on a PSR under

these circumstances is proper," but noted prior dicta indicating

that, even though police records are not "permissible Shepard

materials," "we would approve of the use of a PSR's summary of

police reports to support the characterization of a predicate


                                   -50-
offense when the defendant did not object to the PSR."              

n.6.

              This arguable approval in Davis of unchallenged police

reports in a PSR to establish the character of a predicate offense

is weakly grounded in our precedent and contrary to Shepard.              The

precedent cited for this proposition is Jimenez, where the panel's

primary focus was on whether challenged predicate crimes listed in

the PSR were adequately verified, not on the convictions' character

for the modified-categorical inquiry.          See 

(noting appellant's argument that "the district court erred when it

relied on the PSI Report for proof of these prior convictions").

Jimenez did not argue that either of the challenged convictions was

"for an offense that falls outside the contemplation of the career

offender provisions."         

n.3; see also 

(observing

that "appellant has made no argument, either in the lower court or

in     this   court,    that    his   prior   convictions,    if    properly

substantiated,     do   not    qualify   as   convictions   for    controlled

substance offenses").19


       19
         The precedent cited by the Jimenez panel further
demonstrates that the issue addressed there was whether the
convictions were properly included in the PSR, not whether the
convictions were eligible predicates for enhancement. To support
its statement that the PSR provides "competent evidence of the fact
stated and, thus, is sufficient proof of that fact," the court
cited United States v. Pelletier, 

, 202-03 (1st Cir.
2006), and United States v. Cordero, 

, 701 (1st Cir.
1994), which involved challenges to the fact (Pelletier) or
constitutionality (Cordero) of a 

.


                                      -51-
           Davis thus contemplates disregarding the Supreme Court's

explicit   restriction   on   what   documents   may   be   consulted   to

determine the nature of a predicate conviction under a divisible

statute, allowing reliance on materials (i.e., police reports) that

have been expressly designated as unacceptable for this purpose.

See 

.     In my view, however, we are not free

to depart from the Supreme Court's methodology for determining the

eligibility of a predicate offense, even in the context of plain

error.     That   methodology,   designed   to   ensure   that   prolonged

sentences are justified, has substantive importance. See 

(stating that the defendant's failure to object did

not "render the PSR's description more reliable in establishing the

requisite" predicate).    That is why, when a sentencing judge errs

by failing to demand Shepard-approved proof that the defendant's

conviction under a divisible statute was for a predicate offense,

a sentencing enhancement cannot stand if its only foundation is the

defendant's PSR, at least when the report is not drawn from

approved sources.    Accord 

("We have little

trouble concluding that a sentencing court may not rely on a PSR's

description of a defendant's pre-arrest conduct that resulted in a

prior conviction to determine that the prior offense constitutes a




                                  -52-
'crime of violence' under U.S.S.G. § 4B1.2(a)(1), even where the

defendant does not object to the PSR's description.").20

           The Turbides-Leonardo approach, however, indirectly gives

Serrano's PSR dispositive weight by rejecting his claim that the

record does not support classifying his Article 3.1 offense as a

crime of violence.    The district court accepted the base offense

level calculation recommended in the PSR, which was premised on

multiple prior convictions -- including under Article 3.1 -- for

crimes of violence.      In failing to require proof of the actual

basis for Serrano's convictions, the district court necessarily

deferred to the PSR's depiction of his offenses.        By leaving the

district court's reliance on the PSR undisturbed (unless the

defendant comes forward with contrary evidence), we are sanctioning

that deference.   Yet, as I have shown, any suggestion in our cases

that such deference may be permissible developed from inapplicable

precedent and, more importantly, contravenes the Supreme Court's

specific   delineation    in   Shepard   of   the   records   that   may




     20
       In Dantzler, the Second Circuit reserved judgment on whether
a PSR may be a permissible source of evidence of the nature of a
predicate conviction if the report "was derived in whole, or in
large part," from Shepard-approved 

. I
likewise intimate no view on that scenario. But see, e.g., 

(stating that a PSR may be used for enhancement
purposes if it "'bears the earmarks of derivation from Shepard-
approved sources,'" at least where the defendant "'never raised the
slightest objection either to the propriety of its source material
or to its accuracy'" (quoting United States v. Thompson, 

, 285 (4th Cir. 2005)).

                                 -53-
substantiate the eligibility for enhancement of a conviction under

a divisible statute.

             In light of this analysis, the district court plainly

erred in deferring to the PSR -- or, as described above, in failing

to demand acceptable forms of proof from the government.               The

defendant's failure to make a timely objection imposes on him the

burden to show that he suffered from the court's error.         We should

conclude that his burden is easily met -- and a resentencing

required -- if the court relied on such convictions to enhance his

sentence.

                                   II.

             In examining a claim of plain error in the context of the

modified categorical approach, we cannot lose sight of the courts'

obligation to ensure that extended incarceration is imposed only

when   the   government   has   proven   that   it   is   justified   by   a

defendant's criminal history.        We can, and should, meet this

obligation by adopting the Second Circuit's (and other courts')

approach that a "defendant's failure to object d[oes] not cure the

Government's failure to submit the proper evidence." 

(describing the holding in 

).            As

I have explained, requiring the government to retain its burden to

justify a sentencing enhancement does not result in excusing the

defendant's default. Nor will a finding of prejudicial plain error

and the required relief -- at most, a new sentencing proceeding --


                                  -54-
impose undue burden on the court.        Although few sentences may be

changed through this process, "the fairness, integrity, [and]

public   reputation   of   judicial   proceedings"   will   be   enhanced.

    (internal quotation marks omitted).

           In this case, where variants of Article 3.1 do not

include the requisite element of violence, we should not reject

appellant's claim on the ground that some offenses under the

statute would qualify as predicate crimes of violence.                The

district court committed plain error when it relied on Serrano's

conviction under that divisible statute to justify an increased

term of imprisonment in the absence of approved forms of evidence

of the nature of his particular crime.          The court should have

insisted that the government shoulder its burden to substantiate

that Serrano's conviction was in fact a qualifying predicate.

Hence, on en banc review, this court should hold that Serrano is

entitled to a new sentencing proceeding where the government may

seek to show that his conviction was for a crime of violence.




                                  -55-