United States Court of Appeals
                      For the First Circuit


No. 17-1258

                    UNITED STATES OF AMERICA,

                            Appellee,

                                v.

                   JEAN CARLOS RIVERA-MORALES,
                           a/k/a CARLI,

                      Defendant, Appellant.


          APPEAL FROM THE UNITED STATES DISTRICT COURT
                 FOR THE DISTRICT OF PUERTO RICO

         [Hon. Francisco A. Besosa, U.S. District Judge]


                              Before

                       Howard, Chief Judge,
                Selya and Barron, Circuit Judges.


     Eleonora C. Marranzini, Assistant Federal Public Defender,
with whom Eric Alexander Vos, Federal Public Defender, and Vivianne
M. Marrero, Assistant Federal Public Defender, Supervisor, Appeals
Section, were on brief, for appellant.
     Julia M. Meconiates, Assistant United States Attorney, with
whom Rosa Emilia Rodríguez-Vélez, United States Attorney, and
Mariana E. Bauzá-Almonte, Assistant United States Attorney, Chief,
Appellate Division, were on brief, for appellee.


                           May 29, 2020
             SELYA, Circuit Judge.          The warrant requirement of the

Fourth Amendment is among the most important of the constitutional

protections enumerated in the Bill of Rights.                  Even so, not all

government    intrusions    into    seemingly        private    areas,    whether

physical or virtual, trigger the warrant requirement.                    One such

type of intrusion, seldom encountered, is embodied in the private

search doctrine.     In general terms, that doctrine provides that

law enforcement officers may, without a warrant, examine evidence

that a private party has unearthed and made available to them, as

long as their actions remain within the scope of the antecedent

private search.     See United States v. Jacobsen, 

, 115,

118-20 (1984); United States v. Powell, 

, 5 (1st Cir.),

cert. denied, 

(2018).

             This appeal requires us to apply the private search

doctrine in the evolving context of modern technology.                        At a

granular   level,   it   concerns       a   wife's    search   of   a   cellphone

belonging to her husband (defendant-appellant Jean Carlos Rivera-

Morales), leading to her discovery of a disturbing video.                      The

wife then brought the cellphone to the authorities and directed

their attention to the video.           Her actions paved the way for the

defendant's    indictment   on     a    charge       of   production     of   child

pornography.      After the district court denied the defendant's

motion to suppress the video, see United States v. Rivera-Morales,




                                       - 2 -


, 170 (D.P.R. 2015),1 a jury found him guilty

as charged.

               The defendant now appeals.    After careful consideration,

we affirm the district court's denial of the motion to suppress

under the private search doctrine and, thus, affirm his conviction.

We also affirm the defendant's sentence.

I. BACKGROUND

               We briefly rehearse the relevant facts and travel of the

case.       With respect to suppression, our account gives credence to

the facts supportably found by the district court.               See United

States v. Coombs, 

, 443 (1st Cir. 2017).             As to the

assignments of sentencing error, we draw the facts from the trial

record, the undisputed portions of the presentence investigation

report (PSI Report), and the transcript of the disposition hearing.

See United States v. Flete-Garcia, 

7, 21-22 (1st Cir.),

cert. denied, 

(2019).

               On the evening of January 5, 2015, the defendant and his

then-wife,       Beskis   Sánchez-Martínez   (Sánchez),   were    at   home.

Sánchez used the defendant's cellphone, an Apple iPhone, to unblock

a part of a game that she was playing on her own cellphone.            While


        1
       The suppression hearing was held before a magistrate judge,
who issued a report and recommendation (R&R). On de novo review,
the district court adopted the magistrate judge's findings of fact
and conclusions of law.     For ease in exposition, we take an
institutional view and refer to those findings and conclusions as
those of the district court.


                                    - 3 -
on the defendant's cellphone, she elected to scroll through his

photographs to find pictures of their pets that he had forwarded

to her earlier that day.        In the process, she encountered a

photograph of the defendant's penis next to a pair of blurry hands.

When she confronted the defendant about the photograph, he told

her that it was old.

             Still upset, Sánchez retrieved the defendant's cellphone

later that night.     In the recently deleted files, she found the

same photograph.     She also found a fourteen-second video of their

six-year-old daughter masturbating the defendant.       Enraged, she

demanded that the defendant leave the house — but she kept his

cellphone.

             Sánchez proceeded to contact her uncle, a municipal

police officer, so that he could explain the process for reporting

what she had uncovered.2      Following his advice, she repaired to

the local police station.      She told the desk officers what had

transpired and, "out of anger and upset," decided to show them the

blurry photograph and the video.         Sánchez held the cellphone

throughout the conversation, and the desk officers did not see

anything besides the photograph and the video.      Taken aback, the




     2 There is no indication in the record that Sánchez's uncle
was acting in a professional capacity. His advice was avuncular,
not official.


                                 - 4 -
desk officers arranged for Sánchez to meet with Puerto Rico Police

Officer Aileen Pérez-Ramos (Officer Pérez) the following morning.

             Sánchez and Officer Pérez met at the appointed time.

Sánchez   explained     what   had   occurred       overnight.    On   her   own

initiative, Sánchez pulled the cellphone out of her purse and,

while holding it in her hand, played the video for Officer Pérez,

who then instructed Sánchez to turn off the cellphone.                  Officer

Pérez took the cellphone from Sánchez and asked her to return the

next day for an interview at the district attorney's office.

             The following day, Sánchez and Officer Pérez met with

Agent Pedro Román (a representative of Immigration and Customs

Enforcement).        Officer Pérez gave the cellphone to Agent Román,

and the three of them headed to the district attorney's office and

met with a coterie of federal and local officials.                      Sánchez

recounted the events of January 5.                  She then asked for the

cellphone so that she could play the video.               Agent Román passed

the cellphone to Sánchez, who pulled up the video.                     With the

cellphone in the hands of either Sánchez or Officer Pérez — there

is conflicting testimony on this point — the assemblage watched

the video.    Agent Román then reclaimed the cellphone.           As was true

of her interview with Officer Pérez, Sánchez did not show the group

anything other than the video.

             Later    the   same   day,   federal    agents   (accompanied    by

Officer Pérez) interviewed the defendant at the police station.


                                     - 5 -
After waiving his Miranda rights, see Miranda v. Arizona, 

(1966), the defendant admitted having recorded the video.                 At

the conclusion of the interview, the defendant consented to a

search of his cellphone.

             In due course, a federal grand jury sitting in the

District of Puerto Rico handed up a single-count indictment, which

charged the defendant with production of child pornography.                 See

18 U.S.C. § 2251(b).       The defendant moved to suppress the video

and   his   ensuing   confession     on   the    ground   that   the   officers

transgressed the Fourth Amendment by accessing the video on his

cellphone without a warrant and prior to obtaining his consent.

The district court referred the motion to a magistrate judge, see

28 U.S.C. § 636(b)(1)(B); Fed. R. Crim. P. 59(b)(1), who held a

two-day evidentiary hearing.       The magistrate judge took the matter

under advisement and subsequently issued the R&R, recommending

that the district court deny the motion pursuant to the private

search doctrine.      See 

.            The

magistrate    judge's    rationale    was       that   Sánchez   searched    the

cellphone as a private party, and the officers' subsequent viewings

of the video did not exceed the scope of her search.             See

defendant's objection, the district court adopted the R&R and

denied the motion to suppress.

             Conceding his factual guilt but seeking to preserve his

right to appeal the denial of his motion to suppress, the defendant


                                     - 6 -
explored the possibility of entering a conditional plea.     See Fed.

R. Crim. P. 11(a)(2).      The government withheld its consent, and

the defendant instead proposed that he would waive his right to

trial by jury.     When the district court was about to convene the

bench trial, the government stated that it intended to call

witnesses to testify because the defendant had not stipulated to

all of the relevant facts. In light of this development, the court

continued the matter and decided to impanel a jury.       Sánchez was

the sole witness at the two-day jury trial, and her testimony was

supplemented by a multipart factual stipulation.      The defendant

conceded his guilt in his opening statement and, not surprisingly,

the jury returned a guilty verdict. With an eye toward sentencing,

the district court ordered the preparation of the PSI Report.

           In the PSI Report, the probation officer provided more

lurid details about the defendant's sexual abuse of his daughter.

On at least three occasions between September and December of 2014,

the defendant told his daughter to touch his penis, which he called

a "toy."   He rubbed his penis against her vagina or anus multiple

times and digitally penetrated her vagina at least once.      The PSI

Report also contained the probation officer's calculation of the

defendant's guideline sentencing range (GSR).        It recommended

offense-level enhancements to account for the victim's age, see

USSG §2G2.1(b)(1)(A), the commission of a sexual act, see USSG

§2G2.1(b)(2)(A),     the   parent-child   relationship,    see   USSG


                                - 7 -
§2G2.1(b)(5), and the pattern of activity involving prohibited

sexual conduct, see USSG §4B1.5(b)(1).3     The PSI Report suggested

a two-level downward adjustment for acceptance of responsibility

under USSG §3E1.1(a) but not the additional one-level reduction

under USSG §3E1.1(b).      The defendant objected to the proposed

pattern-of-activity enhancement and requested the additional one-

level discount for acceptance of responsibility.

            At the disposition hearing, the district court sustained

the defendant's objection to the pattern-of-activity enhancement.

It denied his request for the third-level reduction for acceptance

of responsibility under section 3E1.1(b), noting the extensive

pretrial effort that the government had devoted to the case.        This

fine-tuning produced a GSR of 235 to 293 months.        Emphasizing the

tender age of the victim and her relationship to the defendant,

the government sought a sentence of 360 months (the statutory

maximum).    The defendant sought a sentence of 180 months (the

statutory   minimum).    The   court   imposed   a   360-month   term   of

immurement, explaining that the upward variance was warranted

because the defendant had digitally penetrated the victim, his own




     3  All sentencing guideline references are to the 2016
Guidelines Manual, which was in effect at the time of the
disposition hearing. See United States v. Harotunian, 

, 1041-42 (1st Cir. 1990) ("Barring any ex post facto problem,
a defendant is to be punished according to the guidelines in effect
at the time of sentencing.").


                                - 8 -
six-year-old daughter, and rubbed his penis against her vagina.

This timely appeal followed.

II. ANALYSIS

             The defendant's claims of error fall into two buckets.

First, he challenges the district court's denial of his motion to

suppress.    Second, he challenges his sentence as both procedurally

flawed   and    substantively      unreasonable.            We     address      these

challenges sequentially.

                               A. Suppression.

             The defendant's challenge to the denial of his motion to

suppress rests on a claim that the district court misapplied the

private search doctrine.         He contends that the law enforcement

officers who viewed the video on his cellphone lacked a virtual

certainty    that,   while    doing     so,    they   would      not   come    across

additional (still-private) information.               Without such a degree of

certainty, the defendant's thesis runs, the officers' viewings of

the video offended the Fourth Amendment.               In grappling with this

challenge, we assay the district court's findings of fact for clear

error and its conclusions of law de novo.                See United States v.

Hughes, 

, 434 (1st Cir. 2011).

             We anchor our analysis in constitutional bedrock:                    the

Fourth Amendment protects "[t]he right of the people to be secure

in   their     persons,      houses,     papers,      and     effects,        against

unreasonable searches and seizures."                  U.S. Const. amend. IV.


                                       - 9 -
However, this prohibition only pretermits government action.    See

; United States v. Silva, 

, 18

(1st Cir. 2009).   Thus, the Fourth Amendment is not implicated

when a private party undertakes a search or seizure, regardless of

the reasonableness vel non of her conduct, unless she is acting as

a government agent.   See 

; 

.

          To determine whether a private party is acting as a

government agent when conducting a search, we examine all of the

attendant facts and circumstances.    See 

-19.

The case law teaches that three factors are especially relevant to

this analysis: "the extent of the government's role in instigating

or participating in the search, its intent and the degree of

control it exercises over the search and the private party, and

the extent to which the private party aims primarily to help the

government or to serve its own interests."

(quoting

United States v. Pervaz, 

, 6 (1st Cir. 1997)).    That the

government has an interest in the outcome does not, without more,

convert an otherwise private search into state action.     See

case, Sánchez was plainly acting as a private

party, not a government agent, when she accessed the defendant's

cellphone at their marital domicile and discovered the video.   The

defendant does not argue to the contrary and, at any rate, this

conclusion is amply supported by the district court's factual


                             - 10 -
findings.   Sánchez first used the cellphone to unblock a game that

she was playing and then decided to look for photographs of her

pets.   She accessed the cellphone a second time because she was

unhappy with the defendant's response when she confronted him about

the blurry photograph.    In other words, her motives for handling

the cellphone and accessing the photographs while at home were

purely personal.     By the same token, the government did not

instigate, participate in, or control Sánchez's examination of the

contents of the cellphone on those occasions.       In fact, Sánchez

had no communication with any government representative until

after she had discovered the video.     Because Sánchez was acting in

a private capacity, her use of the defendant's cellphone while at

home and her consequent discovery of the video did not implicate

the Fourth Amendment.    See

of course, the instances in which Sánchez

accessed the defendant's cellphone in order to show the video to

various law enforcement officers.       Three such instances occurred

before the defendant consented to a search of his cellphone:

first, when Sánchez went to the police station and reported the

video to the desk officers; second, when Sánchez repeated her story

to Officer Pérez the following day; and third, when Sánchez met

with several law enforcement officers at the district attorney's

office. Although the parties' arguments lump these three incidents




                               - 11 -
together, we regard the first incident as analytically distinct —

and we start there.

            We think it manifest that Sánchez was still acting as a

private party when she accessed the video to show it to the desk

officers.     Even though Sánchez was advised to go to the police

station by her uncle (a municipal police officer), he was not

acting in an official capacity and did not accompany her on that

journey.     Nor is there any evidence that he directed her to play

the video upon her arrival. For aught that appears, Sánchez sought

out the police on her own initiative in order to inform them about

her husband's illegal behavior and protect her daughter.   When she

arrived at the station, she told the desk officers what she had

discovered and then, "out of anger and upset," showed them the

video.      The desk officers did not touch the cellphone, which

remained in Sánchez's possession throughout her visit.

            Nothing about this series of events indicates that the

government instigated, participated in, or controlled Sánchez's

accessing of the cellphone by, for example, asking her to pull up

the video. Nor does the record support an inference that Sánchez's

primary intent was to assist the government.   To the contrary, she

displayed the video to the desk officers out of pique.   Her motive

was purely personal, and although it may have overlapped with the

government's goal of combatting child pornography, this confluence

of interests did not, by itself, transmogrify Sánchez into a


                                - 12 -
government agent.   See United States v. Cameron, 

, 638

(1st Cir. 2012).

          To say more about this viewing would be to paint the

lily.   Because Sánchez was not acting as a government agent when

she accessed the video to show it to the desk officers, there is

no plausible basis for concluding that those officers violated the

Fourth Amendment.     Any other conclusion would contravene the

settled principle that law enforcement officers are free to accept

evidence voluntarily delivered to them by a private party — even

evidence for which they would not have been able to search in the

absence of a warrant — without crossing the line into forbidden

Fourth Amendment territory.    See Coolidge v. New Hampshire, 

, 487 (1971); cf. Spencer v. Roche, 

, 149 (1st

Cir. 2011) (explaining that "a police officer's observation of an

item in plain view does not constitute a search so long as the

officer makes his observation from a lawful vantage point").

          That ends this aspect of the matter.   Sánchez sought out

the police on her own initiative in order to volunteer evidence of

the defendant's misconduct.   During her conversation with the desk

officers at the station — where the officers undoubtedly had a

right to be — she accessed the video and played it for them.    In

those circumstances, the officers cannot be said to have conducted

a "search."   To paraphrase the Supreme Court, when Sánchez "of her

own accord produced [the video] for inspection, rather than simply


                               - 13 -
describing [it], it was not incumbent on the police to stop her or

avert their eyes."    

; see 

(explaining that officer's "viewing of what a

private party had freely made available for his inspection did not

violate the Fourth Amendment").

          This holding does not get the government out of the

woods.   Law enforcement officers involved in the investigation

reexamined the video on two subsequent occasions prior to obtaining

the defendant's consent. On one occasion, Sánchez showed the video

to Officer Pérez.    On the other occasion, she showed it to a group

of officers at the district attorney's office.    In each instance,

Sánchez — as part of an investigatory interview arranged by law

enforcement personnel — played the video while describing what had

occurred on the evening of January 5.   For present purposes, these

two reexaminations occurred under materially indistinguishable

circumstances.4   Consequently, we treat them together.




     4The district court's factual findings reveal one potentially
significant distinction between the two interviews. While Sánchez
had custody of the cellphone until the end of the interview with
Officer Pérez, Agent Román had custody of it throughout the
interview at the district attorney's office (and Officer Pérez may
have held it while the video was playing). Because the defendant
does not contest that the government had lawful possession of the
cellphone and only Sánchez accessed its contents, we agree with
the district court that the officers' handling of the cellphone
during the latter interview does not tip the Fourth Amendment
balance. See 

n.8.


                               - 14 -
              Before embarking upon this joint treatment, we think it

useful to narrow the circumference of the critical issue.             To this

end, we assume for argument's sake that Sánchez was acting as a

government agent when she accessed and played the video during

these interviews.       We hasten to add that such an assumption does

not, by itself, place the officers' warrantless reexaminations of

the   video    in   constitutional     jeopardy.     After   all,    not   all

intrusions into personal privacy attributable to the government

are searches that implicate the Fourth Amendment.                   See Vega-

Rodriguez v. P.R. Tel. Co., 

, 178 (1st Cir. 1997).

Here, the government identifies one such intrusion — embodied in

the private search doctrine — and argues that the reexaminations

of the video fall squarely within the protections of that doctrine.

The district court agreed, and we examine its ruling without

further ado.

              The private search doctrine rests on a solid doctrinal

foundation.         A   government    intrusion    into   personal    privacy

constitutes a Fourth Amendment search only when it offends an

individual's reasonable expectation of privacy.           See United States

v. Hood, 

, 90 (1st Cir. 2019); 

.       When a private party examines particular evidence and

then invites the government to inspect what she has found, the

private party has frustrated any reasonable expectation of privacy

that an individual might have had in that evidence.           See Jacobsen,


                                     - 15 

, 120 n.17.      As a result, the government does

not conduct a search when it does no more than examine particular

evidence that a private party has already inspected and made

available to it, even if that evidence once engendered a reasonable

expectation of privacy.5    See id.; 

.

          The legality of the government's actions in examining

the evidence depends on the degree — if any — to which those

actions "exceed[] the scope of the private search."       

.   In the classic case, the government does not perform

a search if its examination of the evidence is "coextensive with

the   scope"   of   the   antecedent   private   search   and,   viewed

objectively, "there is 'a virtual certainty that nothing else of

significance' could be revealed" through its actions.       

(quoting 

); see United States

v. D'Andrea, 

, 9 & n.12 (1st Cir. 2011) (explaining

objective nature of "virtual certainty" standard).         Conversely,

when the government exceeds the scope of the private search, it




      5Since the rationale for the private search doctrine derives
from the existence vel non of an individual's reasonable
expectation of privacy, one may wonder about the doctrine's
continuing vitality in light of the Supreme Court's decision in
United States v. Jones, 

, 404-05 & 411 n.8 (2012)
(holding that a physical intrusion into a constitutionally
protected area for an investigatory purpose should be deemed to
constitute a Fourth Amendment search).         Here, however, the
defendant does not ask us to reconsider the private search doctrine
in light of Jones, and we take no view on the issue.


                                - 16 -
conducts     its    own   search,    which     requires    independent   Fourth

Amendment justification.       See 

.

             In the case at hand, the critical question is whether

the actions of the officers, in effectively accessing and viewing

the video during the two reexaminations, fell within the scope of

Sánchez's private search.          The district court said that they did.

See 

.               It found that, during

both interviews, Sánchez pulled up exactly the same video that she

had discovered at home, showed that video — and nothing else — to

the officers, and accessed no other material on the defendant's

cellphone.     See

       These findings are consistent with

the record, and they show beyond any doubt that the government

intrusions into the defendant's cellphone remained within the

scope of Sánchez's private search.              See 

-6

(finding no Fourth Amendment violation when government viewed

without a warrant same screenshots that private party had seen and

forwarded). In fact, the officers saw less than Sánchez did during

her private search, as she went through a number of photographs on

the cellphone as well.

             This   leaves,   of    course,    the   imbricated     question   of

whether a reasonable officer would have been virtually certain

that   he   would    have   seen    on   the    cellphone    only   information

previously observed by Sánchez.              Neither the Supreme Court nor

this court has set fixed parameters as to what constitutes "virtual


                                     - 17 -
certainty" in this context.         The term, though, implies something

less than absolute confidence.            This understanding of virtual

certainty    necessarily       follows   from   the     type    of   government

intrusion authorized by the private search doctrine, which permits

an officer to examine evidence that is not in plain view.                   See

, 120 n.17.          Because the officer must

rely exclusively on what the private searcher has reported, he can

never be absolutely sure of what he will find.                 Police officers,

after all, are not omniscient.

            Seen   in   this    light,   we   believe    that     the   "virtual

certainty" inquiry requires a common-sense determination into

whether there is anything more than a remote or highly unlikely

possibility that the officer's actions will uncover something of

significance apart from what the private searcher has found and

reported.    In our view, anything more than a remote and highly

unlikely possibility will dispel the aura of virtual certainty

and, thus, prevent the officer from proceeding with his own

warrantless examination of the evidence.              Cf. United States v.

Ackerman, 

, 1306 (10th Cir. 2016) (finding private

search doctrine inapplicable when government actor "quite easily"

could have come across previously unknown information); United

States v. Lichtenberger, 

, 488-89 (6th Cir. 2015) (same

when "there was a very real possibility" that officer could have

uncovered still-private information).


                                    - 18 -
          In   this    case,   the   "virtual   certainty"   requirement

appears, at first glance, to be satisfied.           Crucially, it was

Sánchez — not one of the officers — who accessed the video during

both interviews.    Because she was familiar with the cellphone and

knew where the video was stored, there was no credible risk that

she would open applications or files other than the video that she

intended to play.     What is more, she had no incentive to show the

officers anything other than the video that was the focal point of

the interviews.       Viewed objectively, the manner in which the

officers reexamined the video ensured that there was no more than

a remote possibility that the intrusions into the defendant's

cellphone would disclose any data stored there beyond what Sánchez

already had seen and reported.

          In an effort to blunt the force of this reasoning, the

defendant argues that the officers could not have been virtually

certain that a notification — such as a calendar appointment or

text message — would not spontaneously pop up on the cellphone's

screen while they were watching the video.6         This is strictly a




     6 In articulating this argument, the defendant focuses solely
on what the officers could have encountered when they viewed the
video. Accordingly, he has waived any contention that the "virtual
certainty" requirement was not satisfied because Sánchez could
have come across pop-up notifications when she turned on the
cellphone and accessed the video. See United States v. Zannino,

, 17 (1st Cir. 1990) ("[I]ssues adverted to in a
perfunctory manner, unaccompanied by some effort at developed
argumentation, are deemed waived.").


                                 - 19 -
theoretical argument:    nothing in the record suggests that such a

notification actually appeared on the screen during either of the

viewings.    We therefore have no occasion to address whether, had

that happened, the Fourth Amendment would have permitted the

government to use information gleaned from the notification in its

prosecution of the defendant.    Instead, we limit our analysis to

the particular species of "pop-up notification" argument that the

defendant has actually made.

            Before wrestling with this argument, we pause to place

it in context.      After the suppression hearing, the defendant

submitted a memorandum to the magistrate judge, in which he

challenged the applicability of the private search doctrine to the

officers' viewings of the video.     In that memorandum, he posited

that the Supreme Court's decision in Riley v. California, 

(2014), required the officers to secure a warrant before

accessing the contents of his cellphone.    Relatedly, he contended

in general terms that the "virtual certainty" requirement was not

satisfied because the magistrate judge could not be sure that the

officers saw nothing on the cellphone but the video. The defendant

renewed those contentions — and only those contentions — in his

objections to the R&R.    At no point during the proceedings below

did he argue that, due to the possibility of pop-up notifications,

the officers could not have been virtually certain that they would




                                - 20 -
see only the video.         On appeal, though, he tries for the first

time to broach that argument.

             Such "[h]opscotching from one theory to another theory

has consequences."      United States v. Pinkham, 

, 137

(1st Cir. 2018); cf. United States v. Dietz, 

, 55 (1st

Cir.    1991)   (warning,     in    context       of   sentencing   appeal,   that

defendant "cannot switch horses mid-stream in hopes of locating a

swifter steed").     When a defendant changes his tune on appeal and

advances before the court of appeals a theory different than the

one that he advanced before the district court, the new theory is

forfeited.      See 

.             That is the situation

here:    careful perscrutation of the record reveals no indication

that the defendant presented his "pop-up notification" argument

face up and squarely in the court below.                     Because review of

forfeited theories is only for plain error, see United States v.

Duarte, 

, 60 (1st Cir. 2001), we apply that stringent

standard here.

             To prevail on plain error review, an appellant must show

"(1) that an error occurred (2) which was clear or obvious and

which not only (3) affected [his] substantial rights, but also

(4) seriously      impaired        the    fairness,      integrity,   or   public

reputation of judicial proceedings."

of "plain

error must carry the devoir of persuasion as to all four of these

elements."      

.


                                         - 21 -
             In this instance, we need not canvass all four elements

of the plain error standard.    For present purposes, it suffices to

note that the defendant's forfeited argument stumbles on the second

element.   Although we readily acknowledge that the officers lacked

absolute certainty that no pop-up notification would appear while

they were viewing the video, "absolute certainty" is not the

benchmark.     Neither party offered a shred of evidence about the

frequency with which pop-up notifications appear on cellphones

and, in the absence of any such evidence, it is plausible to

conclude that the possibility was remote and highly unlikely that

a pop-up notification would appear while the officers were viewing

the fourteen-second video.       Moreover, the "virtual certainty"

requirement aims to ensure that an antecedent private search does

not become "a free pass for the government to rummage through a

person's effects."      

.     It is far from

obvious that the chance that a notification might have appeared on

the screen afforded the officers any opportunity to rummage through

the defendant's private information.      And to cinch the matter, a

criminal defendant generally cannot show that a legal error is

clear or obvious in the absence of controlling precedent resolving

the disputed issue in his favor.         See, e.g., United States v.

Delgado-Sánchez, 

, 10-11 (1st Cir. 2017); United States

v. Amaro-Santiago, 

, 163 (1st Cir. 2016).       Here, no




                                - 22 -
controlling   precedent    requires      us    to    embrace     the    defendant's

position.

            The Jacobsen Court established the framework for the

private search doctrine in the process of evaluating an officer's

examination of a package.        

.          The Court did not

define "virtual certainty," and it is not immediately apparent how

that concept translates from the context of a static object like

a package to the ever-changing screen on a cellphone.                       Our two

prior opinions on the private search doctrine inch closer to the

digital    realm,   see   

-6    (dealing     with

screenshots sent to government entity); 

-

10 (dealing with pictures stored on a website), but neither of

them provides any direct guidance on how to think about virtual

certainty vis-à-vis cellphones.          On this undeveloped record, the

lack of clarity in the case law dashes the defendant's hopes of

demonstrating plain error.

            A related point is worth making. Because most cellphones

are able to display notifications spontaneously, the defendant is

inviting    us,   in   effect,    to    deem    government       inspections     of

information stored on a cellphone categorically exempt from the

prophylaxis of the private search doctrine.                It is neither clear

nor obvious that we must accept this invitation.                       The only two

courts of appeals that have addressed the private search doctrine

in the cellphone context expressed no hesitance in permitting


                                    - 23 -
tailored government inspections of information stored on such

devices.     See United States v. Suellentrop, 

, 1050

(8th Cir. 2020); United States v. Sparks, 

, 1334-36

(11th Cir. 2015).

             The Supreme Court's decision in Riley does not demand a

different result.          There, the Court addressed the question of

whether another Fourth Amendment doctrine — the search incident to

arrest doctrine — permitted the warrantless inspection of digital

information stored on a cellphone.               See 

.

To answer this question, the Court balanced the degree to which

the search of the contents of a cellphone intrudes upon individual

privacy    against      the    extent   to   which   such     a    search     protects

legitimate government interests in the context of an arrest.                       See

-86. 
        The Court acknowledged that the search of the

contents    of    a    cellphone    allows    the    government        to    access   a

significant amount of highly personal information.                          See
 id. at

386. 
  On the other pan of the scale, the Court noted that such a

search does not substantially advance the government interests

that justify the search incident to arrest doctrine (the protection

of officer safety and the safeguarding of evidence).                           See
 id.

Balancing these 
considerations, the Court held that the government

could not rely on the search incident to arrest doctrine to justify

a   warrantless       search   of   information      stored       on   an   arrestee's

cellphone.       See
 id.


                                        - 24 
-
            Although Riley suggests caution in applying the private

search doctrine to cellphones and other types of digital devices,

it does not either create or suggest a categorical rule to the

effect that the government must always secure a warrant before

accessing the contents of such a device.                 Cf.
 id. at 401-02
(stating    that   "case-specific      exceptions    may     still   justify   a

warrantless search of a particular phone").             As we explain below,

we do not believe that Riley unequivocally requires that we exclude

government inspections of evidence contained on cellphones from

the private search doctrine.

            To begin, it is not obvious that Riley's reasoning is

directly applicable to the question before us.                The Riley Court

applied the balancing test that typically is used when deciding

whether to exempt a particular type of search from the warrant

requirement, see
 id. at 385 
— yet a government inspection of

evidence that falls within the ambit of the private search doctrine

does not constitute a search in the first place, see 
Jacobsen, 466

U.S. at 117-20
.      Furthermore, the justification for the private

search doctrine appears to apply with full force to digital

information stored on a cellphone.            When a private party conducts

a search and then invites the government to examine what she has

found,     the   government   does    not     intrude   on    any    reasonable

expectation of privacy by accepting the invitation, regardless of

where the evidence is located.         See
 id.    Last — 
but far from least


                                     - 25 -
— allowing the government to inspect the contents of a cellphone

under the private search doctrine does not necessarily risk the

exposure of a significant quantity of personal information.            If

the government exceeds the scope of the antecedent private search

and instead rummages through the cellphone, the private search

doctrine will not protect its actions from the strictures of the

Fourth Amendment.      See 
Sparks, 806 F.3d at 1336 
(holding that

private search doctrine did not authorize officer to look at video

on cellphone that private searcher had not previously seen); cf.

Lichtenberger,   786   F.3d   at   488-89 
   (finding   Fourth   Amendment

violation when, after defendant's girlfriend found photographs on

his laptop computer, she showed certain photographs to officer but

could not say these were ones she had viewed earlier).

          We summarize succinctly.          Given the targeted manner in

which the officers acted, it is neither clear nor obvious that the

possible appearance of a pop-up notification on the defendant's

cellphone was sufficient to dispel the officers' virtual certainty

that they would see no other information of significance when they

accessed and viewed the video.          The defendant has, therefore,

failed to show that the district court plainly erred in concluding

that the "virtual certainty" requirement of the private search

doctrine was satisfied with respect to the reexaminations of the

video.




                                   - 26 -
             No more need be said.   We hold that the desk officers'

viewing of the video was not a Fourth Amendment search because

they merely observed evidence that Sánchez, a private party, freely

showed to them.      We further hold that with respect to the two

reexaminations of the video during the subsequent investigatory

interviews, the district court supportably determined that the

officers remained within the scope of Sánchez's antecedent private

search.   Nor did the district court plainly err in finding that

there was a virtual certainty that the officers would see only

information previously observed by Sánchez on the cellphone. Since

the district court appropriately found that the officers did not

violate the Fourth Amendment either by examining or by reexamining

the video, we uphold its denial of the defendant's motion to

suppress.7

                            B. Sentencing.

             We now train the lens of our inquiry on the defendant's

challenges to his 360-month term of immurement.     Appellate review

of claims of sentencing error involves a two-step pavane.        See

United States v. Flores-Machicote, 
706 F.3d 16
, 20 (1st Cir. 2013).


     7 Because we resolve the defendant's challenge to the denial
of his motion to suppress under the private search doctrine, we
have no occasion to address the government's alternative arguments
that Sánchez had actual authority to consent to the officers'
inspection of the defendant's cellphone or that, even if the
officers violated the Fourth Amendment, the denial of the motion
to suppress should be upheld under the inevitable discovery
doctrine.


                                - 27 -
We first examine any assignments of procedural error.             See
 id.   If

the 
sentence passes procedural muster, we next weigh any challenge

to its substantive reasonableness.          See
 id.

            At both 
stages of the sentencing inquiry, we review

preserved claims of error for abuse of discretion.              See
 id.     The

abuse-of-discretion 
standard is not monolithic:              within it, we

review the sentencing court's findings of fact for clear error and

questions    of    law   (including   the    court's    interpretation      and

application of the sentencing guidelines) de novo.              See
 id.

            1. Claims 
of Procedural Error.            The defendant's first

claim of procedural error concerns the district court's denial of

the one-level downward adjustment for acceptance of responsibility

under USSG §3E1.1(b).        He argues that he was entitled to this

adjustment because he admitted his culpability before he was

charged and attempted to avert the necessity for a jury trial by

proposing a conditional plea and (when that proved infeasible) by

attempting to waive a jury.

            To put this argument into perspective, we first describe

the   sentencing    guidelines'   two-tiered      system   to    account    for

acceptance of responsibility.         See United States v. Meléndez-

Rivera, 
782 F.3d 26
, 29 (1st Cir. 2015).           At the first tier, the

defendant is entitled to a two-level downward adjustment in his

offense level when the sentencing court determines that he has

"clearly    demonstrate[d]    acceptance     of   responsibility     for    his


                                  - 28 -
offense."     USSG   §3E1.1(a).     If     the    defendant    receives   this

adjustment and if his offense level (calculated without reference

to the first-tier adjustment) is sixteen or more, the second tier

becomes relevant.    See USSG §3E1.1(b).          That tier contemplates a

further one-level discount

            upon motion of the government stating that the
            defendant has assisted authorities in the
            investigation or prosecution of his own
            misconduct by timely notifying authorities of
            his intention to enter a plea of guilty,
            thereby permitting the government to avoid
            preparing for trial and permitting the
            government and the court to allocate their
            resources efficiently.


Id.

            At first 
blush, the language of both section 3E1.1(b)

and the accompanying guideline commentary appears to make the

additional one-level reduction contingent on the government's

affirmative decision to file a motion.           See id.; see also
 id. cmt.

n.6 
("Because the Government is in the best position to determine

whether the defendant has assisted authorities in a manner that

avoids preparing for trial, an adjustment under subsection (b) may

only be granted upon a formal motion by the Government at the time

of sentencing.").    But in practice, a district court retains some

ability to grant the reduction even if the government abjures such

a motion.    See 
Meléndez-Rivera, 782 F.3d at 30
.             This ability is

narrowly circumscribed:    a sentencing court may exercise it only

"when the government's withholding of the predicate motion 'was


                                  - 29 -
based on an unconstitutional motive' or 'was not rationally related

to any legitimate government end.'"
              

States v.

Beatty, 
538 F.3d 8
, 14 (1st Cir. 2008)).               Under Amendment 775 to

the sentencing guidelines, which took effect on November 1, 2013,

"[t]he government should not withhold such a motion based on

interests not identified in §3E1.1, such as whether the defendant

agrees to waive his or her right to appeal."                  USSG §3E1.1, cmt.

n.6.

             In the case at hand, the district court adopted (without

objection by the government) the PSI Report's recommendation that

the    defendant     receive    a   two-level      downward    adjustment    under

section 3E1.1(a).          That adjustment is not in issue here.          See
 id.

cmt. n.2 
(allowing adjustment when "a defendant goes to trial to

assert and preserve issues that do not relate to factual guilt").

But the government refused to move for the additional one-level

reduction under section 3E1.1(b).            Its reasons were twofold:          it

had to expend appreciable resources responding to the suppression

motion, and the defendant's insistence on a conditional plea forced

it    to   prepare    for    trial.      Notwithstanding       the    government's

recalcitrance,       the    defendant    persisted    in   his   quest    for   the

additional one-level discount.             The court turned a deaf ear to

this request.

             The     parties   spar   over   the    question     of   whether   the

district court appropriately credited the government's need to


                                        - 30 -
respond to the defendant's suppression motion as a justification

for its decision to withhold a section 3E1.1(b) motion. See United

States v. Silva, 
865 F.3d 238
, 244-45 (5th Cir. 2017) (per curiam)

(recognizing unsettled question as to whether section 3E1.1(b)

permits     denial   of   additional      level   for   this    reason      after

promulgation of Amendment 775).           We need not plunge into these

muddy waters, as the government cited its trial preparation as a

further justification for its refusal to file the motion.                Given

this alternative justification, the district court did not abuse

its    discretion    in   denying   the    defendant's     request    for    the

additional one-level reduction.        We explain briefly.

             The defendant bore the burden of persuading the district

court that the withholding of the predicate motion was either based

on    an   unconstitutional   motive      or   unrelated   to   a    legitimate

government end.      See 
Beatty, 538 F.3d at 14-15
; cf. United States

v. Ocasio, 
914 F.2d 330
, 332 (1st Cir. 1990) ("A defendant has the

burden of proving his entitlement to a downward adjustment in the

offense level.").         He makes no argument that the government's

action was based on an unconstitutional motive.            The question thus

reduces to whether the defendant showed that the withholding of

the motion was not rationally related to a legitimate government

end.

             The defendant has failed to carry this burden.                   The

purpose of the section 3E1.1(b) discount is to reward a defendant


                                    - 31 -
"for helping the authorities save resources . . . by a pre-trial

plea of guilty," so it will only be available to a defendant who

elects to stand trial in rare circumstances.               United States v.

Hines, 
196 F.3d 270
, 273-74 (1st Cir. 1999) (explaining that,

absent agreement with government, defendant normally must notify

authorities of willingness to enter unconditional guilty plea to

receive section 3E1.1(b) discount); see USSG §3E1.1(b).                     As a

corollary of this proposition, we think it obvious that the

government may withhold a section 3E1.1(b) motion on the ground

that it had to engage in trial preparation.                See, e.g., United

States v. Rayyan, 
885 F.3d 436
, 440-41 (6th Cir. 2018).

            In this instance, the defendant chose not to plead guilty

and elected to stand trial instead.           Although the trial was brief

and the defendant conceded his guilt, the government still had to

expend resources to prepare.          For example, the government filed

proposed     voir    dire       questions,    proffered     suggested       jury

instructions, prepared and delivered both an opening statement and

summation, and presented the testimony of a witness (Sánchez).                We

discern    nothing   in   the    record   that   calls    into   question    the

government's statement that its decision to withhold a section

3E1.1(b) motion was based at least in part on its legitimate

interest in avoiding this type of trial preparation.             We conclude,

therefore, that the defendant failed to show that the district




                                     - 32 -
court had authority to award the additional one-level reduction in

the absence of a government motion.

          The defendant resists this conclusion.         He points out

that he endeavored to avoid a jury trial by seeking to enter a

conditional plea (preserving his right to appeal the suppression

order), see Fed. R. Crim. P. 11(a)(2), and — when that failed — by

seeking to agree to a bench trial on stipulated facts.           In the

defendant's view, the government had to prepare for trial only

because it spurned his offer of a conditional plea and then refused

to go along with his proposed stipulation.       And he adds that the

denial of the additional one-level discount unfairly penalized him

for exercising his right to seek suppression.

          We recognize that the defendant's decision not to enter

an unconditional guilty plea and his refusal to agree to the

government's preferred stipulation were bound up with his desire

to preserve his ability to appeal the denial of his nonfrivolous

suppression motion.   But just as a defendant has a right, within

broad limits, to make strategic choices, so too the government has

a right to make strategic choices of its own. Thus, the government

was under no obligation to accept either the defendant's offer of

a conditional plea or his preferred version of stipulated facts.

          Here,   moreover,   the   defendant   offers   no   reason   to

believe that the government's strategic choices (such as its

refusal to accept his conditional guilty plea on the terms that he


                               - 33 -
proffered)    were     either    arbitrary       or     rooted    in   improper

considerations.      This is important because the parties' strategic

decisions compelled the government to engage in trial preparation.

Quintessentially, section 3E1.1(b) is meant to reward defendants

who spare the government the expense of trial; and we conclude

that the government could eschew the filing of a section 3E1.1(b)

motion here on the ground that the defendant's strategic choices

made a trial inevitable.

            Last but not least, the denial of the additional one-

level reduction did not improperly penalize the defendant for

seeking to appeal the suppression order.              His decision to preserve

his appellate rights caused the government to expend resources on

a jury trial.     Although the government's ability to withhold a

section   3E1.1(b)    motion    on   that     ground    may   disincentivize   a

defendant from choosing to stand trial, such a disincentive is not

improper.    See 
Beatty, 538 F.3d at 16
.                Having sown the wind

(electing to stand trial to preserve his appellate rights in what

he deemed the most advantageous fashion), the defendant had to

know that he might reap the whirlwind (the risk of losing the

additional one-level reduction for acceptance of responsibility).

He cannot now be heard to complain that this predictable risk

materialized.   See
 id. at 16-17. 
       For these reasons, we hold that

the government rationally justified its decision not to file a

section 3E1.1(b) motion on the basis of its trial preparation.


                                     - 34 -
Thus, the district court did not abuse its discretion in denying

the     additional     one-level          reduction      for     acceptance     of

responsibility.

             The defendant's second claim of procedural error posits

that the district court did not adequately justify the extent of

the upward variance that it imposed.            According to the defendant,

the court's reference to his sexual abuse of his daughter prior to

the recording of the video did not sufficiently explain a variance

of 67 months above the apex of the GSR.                We review this claim of

error for abuse of discretion.             See United States v. Fernández-

Cabrera, 
625 F.3d 48
, 53 (1st Cir. 2010).

             We start with the baseline rule that a sentencing court

has a statutory mandate to "state in open court the reasons for

its imposition of the particular sentence."                  18 U.S.C. § 3553(c).

Withal, this mandate does not mean that a court's explanation must

"be precise to the point of pedantry." United States v. Sepúlveda-

Hernández, 
817 F.3d 30
, 33 (1st Cir. 2016) (quoting United States

v. Turbides-Leonardo, 
468 F.3d 34
, 40 (1st Cir. 2006)).                    Rather,

we appraise the adequacy of a court's explanation "in a practical,

common-sense way," asking whether it has identified the main

factors driving the imposed sentence.
              

States

v.    Dávila-González,       
595   F.3d   42
,   48    (1st    Cir.    2010)).   We

recognize, though, that when a court imposes a variant sentence,

it    must   furnish     a     somewhat     more      detailed       justification,


                                      - 35 -
commensurate with the extent of the variance.             See United States

v. Fields, 
858 F.3d 24
, 31 (1st Cir. 2017).

           Here,   the       district    court   relied    chiefly       on    the

seriousness of the offense, see 18 U.S.C. § 3553(a)(2)(A), to

justify the upward variance.             It thought the upward variance

appropriate "because of what [the defendant] did prior to this

particular incident," that is, digitally penetrating the victim

(his six-year-old daughter) and rubbing his penis on her vagina.8

Although the defendant seeks to characterize this explanation as

encompassing only the prior sexual abuse, we think it apparent

that the court was also concerned about the familial relationship

and the victim's age. These factors plainly compounded the gravity

of the offense.

           It is well-established that "[w]here the record permits

a   reviewing   court   to    identify   both    a   discrete   aspect    of   an

offender's conduct and a connection between that behavior and the

aims of sentencing, the sentence is sufficiently explained to pass

muster under section 3553(c)."           
Sepúlveda-Hernández, 817 F.3d at

33 
(alteration in original) (quoting Fernández-Cabrera, 
625 F.3d


      8The 
district court declined to apply the pattern-of-activity
enhancement under USSG §4B1.5(b)(1) based on this prior abuse, but
the defendant does not contest that this conduct was relevant under
section 3553(a) in determining his sentence. See United States v.
Anonymous Defendant, 
629 F.3d 68
, 76 (1st Cir. 2010) (explaining
that "courts have long been permitted to consider more than charged
conduct in fashioning sentences," including "prior criminal
conduct that has not ripened into a conviction").


                                   - 36 -
at   54).     Though     concise,   the    district   court's    explanation

emphasized    multiple    aspects    of   the   defendant's     conduct   that

rendered it especially heinous.           Because the court made pellucid

that the seriousness of the offense was the driving force in its

sentencing calculus, its explanation was sufficient to satisfy the

statutory mandate.

             The defendant attempts an end run, suggesting that the

district court's explanation was inadequate because his total

offense level already included offense-level enhancements for the

age of the victim, his relationship with the victim, and the fact

that the crime involved a sexual act. This suggestion has a patina

of plausibility: we have held that "when a sentencing court relies

on a factor already accounted for by the sentencing guidelines to

impose a variant sentence, the court must indicate what makes that

factor worthy of extra weight in the defendant's case."              
Fields,

858 F.3d at 32 
(citing United States v. Zapete-Garcia, 
447 F.3d

57
, 60 (1st Cir. 2006)).      Upon careful perscrutation, though, the

defendant's premise collapses.

             Although the defendant's total offense level included

the enhancements that he identifies, the district court expressly

declined to adopt a pattern-of-activity enhancement.                See USSG

§4B1.5(b)(1).     It follows that the GSR did not take into account

the multiple occasions that the defendant sexually abused his minor

daughter.     Put another way, the defendant's GSR would have been


                                    - 37 -
the same had his misconduct been limited to the recording of the

video.    By invoking the uncharged sexual abuse of the victim, the

court     persuasively   articulated    why     it   believed   that   the

defendant's case differed from the generic set of facts that fell

within the heartland of the GSR.       See United States v. Del Valle-

Rodríguez, 
761 F.3d 171
, 177 (1st Cir. 2014).

             The defendant proffers one last claim of procedural

error.     In his sentencing memorandum and at the disposition

hearing, the defendant argued for a downwardly variant sentence of

180 months (the statutory minimum) in order to reflect his personal

characteristics, reward his prompt acceptance of responsibility,

and     avoid   sentencing   disparities      with   purportedly   similar

offenders in the District of Puerto Rico.        He assigns error to the

district court's failure to spell out why it rejected these

arguments.

             We need not tarry.    As a general matter, a sentencing

court is under no obligation either to address every argument that

a defendant advances in support of his preferred sentence or to

walk through each of the section 3553(a) factors one by one.           See

United States v. Cortés-Medina, 
819 F.3d 566
, 571 (1st Cir. 2016).

So, too, although a district court must adequately explain its

sentence, it has "no corollary duty to explain why it eschewed

other suggested sentences."       United States v. Vega-Salgado, 
769

F.3d 100
, 103-04 (1st Cir. 2014).          This makes good sense:      the


                                  - 38 -
sentencing court's rationale often can be discerned by comparing

the   parties'    written    and   oral     arguments   with   the     court's

explanation at sentencing.         See United States v. Murphy-Cordero,

715 F.3d 398
, 401 (1st Cir. 2013).

             At the disposition hearing, the court below made clear

that it had read the parties' sentencing memoranda and allowed

both sides a final opportunity to argue for their preferred

sentences.       After calculating the defendant's GSR, the court

represented that it had considered the section 3553(a) factors.

"Such a statement is entitled to significant weight."                   United

States v. Santiago-Rivera, 
744 F.3d 229
, 233 (1st Cir. 2014).             The

court then mentioned many of the personal characteristics that the

defendant had highlighted in his request for a downward variance.

And   finally,    after     acknowledging     the   defendant's      requested

sentence of 180 months, the court explained that it was imposing

an upward variance because of the defendant's prior sexual abuse

of his six-year-old daughter.        This chain of events gives rise to

only one reasonable inference:         that the court was aware of the

defendant's arguments for a downward variance and found them

wanting.   The court was not obligated to justify its rejection of

the defendant's entreaty for a downward variance in any greater

detail.

             Contrary to the defendant's importunings, our decision

in United States v. Robles-Alvarez, 
874 F.3d 46 
(1st Cir. 2017),


                                   - 39 -
does not demand a different result.             There, the defendant sought

a downward variance from his GSR of life imprisonment to align his

sentence with the 46-month term of imprisonment imposed on the

ringleader of the conspiracy that he had joined.              See
 id. at 52-
53.       We found procedural error due to the court's failure to

mention the defendant's "potentially forceful disparity argument,"

let alone explain why that argument lacked bite.
              Id. at 53.
             The   case    at   hand   and   Robles-Alvarez    are   not   fair

congeners.     Here, the sentencing court explicitly acknowledged the

defendant's request for a downward variance and — unlike in Robles-

Alvarez — we cannot say that the defendant's disparity argument

was "potentially forceful."         We have emphasized that "[a] credible

claim of sentencing disparity requires that the proponent furnish

the   court     with      enough   relevant     information    to    permit   a

determination that he and his proposed comparators are similarly

situated."     United States v. Rodríguez-Adorno, 
852 F.3d 168
, 177

(1st Cir. 2017).          The defendant has not made such a showing.

Although he calculated an average sentence of 204 months for

producers of child pornography in the District of Puerto Rico since

2000, such offenses are infinitely varied.            The record discloses

that the defendant made no attempt to compare himself with these

other offenders on any metric other than the charged offense.9


      9
      We say "charged" offense because the defendant's calculation
appears to include the sentences of offenders who had their


                                       - 40 -
Given   this    chasmal    gap   in   his   disparity   argument,   it   is   a

compelling inference that the court declined to vary downward

because it found the defendant was more culpable than the average

producer of child pornography.

            2. Claim of Substantive Unreasonableness.           This brings

us to the defendant's challenge to the substantive reasonableness

of his sentence.      Echoing one of his claims of procedural error,

he contends that the district court fashioned his sentence without

due consideration of certain mitigating factors (including his

age, forthright acceptance of responsibility, and lack of prior

criminal record).         In light of these factors, he says that his

360-month term of immurement is indefensible.              Inasmuch as the

defendant preserved this claim of error below, our review is for

abuse of discretion.         See United States v. Matos-de-Jesús, 
856

F.3d 174
, 179 (1st Cir. 2017).

            Reasonableness in the sentencing context "is a protean

concept."      United States v. Clogston, 
662 F.3d 588
, 592 (1st Cir.

2011) (quoting United States v. Martin, 
520 F.3d 87
, 92 (1st Cir.

2008)).     As a result, "[t]here is no one reasonable sentence in

any given case but, rather, a universe of reasonable sentencing

outcomes."
      Id.   In appraising 
the substantive reasonableness of




production counts dismissed as part of a plea negotiation. Such
offenders are obviously not similarly situated to the defendant
for the purpose of his sentencing disparity argument.


                                      - 41 -
a particular sentence, then, our task is simply to determine

whether the sentence falls within this broad universe.    See United

States v. de Jesús, 
831 F.3d 39
, 43 (1st Cir. 2016).            When

performing this task, we cannot substitute our judgment of the

appropriate sentence for that of the sentencing court; to the

contrary, we must accord significant deference to the court's

informed determination that the section 3553(a) factors justify

the sentence imposed.   See 
Martin, 520 F.3d at 92
.   This approach

does not change merely because the sentencing court opts to vary

from the GSR.   See 
Santiago-Rivera, 744 F.3d at 234
.    In the last

analysis, a sentence is substantively reasonable so long as the

sentencing court offers a plausible rationale and the sentence

represents a defensible result.     See United States v. Vargas-

García, 
794 F.3d 162
, 167 (1st Cir. 2015).

          Viewed against this backdrop, the defendant's sentence

is unimpugnable.    The district court's explanation for varying

upward, though concise, contained a clear and coherent rationale:

the victim was the defendant's own six-year-old daughter, and he

sexually abused her on multiple occasions.

          The defendant assails this rationale, arguing that it

overlooks certain mitigating factors concerning his history and

characteristics.    This argument misses the mark.        Mitigating

factors cannot be viewed in a vacuum; and although a sentencing

court must consider the full range of relevant factors, "the


                              - 42 -
weighting of those factors is largely within the court's informed

discretion."      
Clogston, 662 F.3d at 593
.                  To this end, we have

admonished      that    a    successful       challenge        to    the    substantive

reasonableness of a sentence "must comprise more than a thinly

disguised attempt by the defendant 'to substitute his judgment for

that of the sentencing court.'"               
Vargas-García, 794 F.3d at 167
(quoting 
Clogston, 662 F.3d at 593
).

             Here,     moreover,        the      district           court     expressly

acknowledged many of the factors that the defendant asked it to

consider, including his age, educational and work history, and

lack of any prior criminal history or drug use.                       Notwithstanding

these   mitigating          factors,    the      court     determined        that   the

seriousness      of    the    offense     justified       a     substantial     upward

variance.     Viewed in the cold light of day, the defendant's real

complaint is not that the court overlooked mitigating factors but,

rather, that it did not assign those factors the weight that he

thinks they deserved.           Such thin forestation is insufficient to

throw   shade    on    the     plausibility       of     the    sentencing      court's

rationale.    See 
Coombs, 857 F.3d at 452
.

             The district court coupled this plausible sentencing

rationale with a defensible result.                 To be sure, the 360-month

sentence — the statutory maximum for the offense of conviction,

see 18 U.S.C. § 2251(e) — was severe, especially for a defendant

who admitted his factual guilt from the start.                         But we do not


                                        - 43 -
presume    that   a    sentence   is    substantively   unreasonable       simply

because it is severe. See 
Flores-Machicote, 706 F.3d at 25
; United

States v. Leahy, 
668 F.3d 18
, 24 (1st Cir. 2012).                Acts ought to

have   consequences,       and    heinous    acts   ought   to      have   severe

consequences.         A sentencing court has discretion, within wide

margins, to impose an upward variance when it determines that the

nature and circumstances of the offense, the need for condign

punishment, and the other section 3553(a) factors warrant a stiff

sentence.    See 
Matos-de-Jesús, 856 F.3d at 180
.

            The court below did not write outside these wide margins

in handing down a 360-month sentence.           The defendant's conduct was

reprehensible in the extreme:            he told his six-year-old daughter

that his penis was a "toy," had her masturbate him at least three

times, and recorded a video of her doing so.                 To make matters

worse, he rubbed his penis against her vagina or anus multiple

times and digitally penetrated her vagina at least once.                    This

sexual abuse will likely cause the victim irreparable mental

anguish.      Under      these    circumstances,     the    court     reasonably

determined that the defendant's aggravated conduct justified a

substantial upward variance.           On this sordid record, we cannot say

that the sentence imposed falls outside the universe of reasonable

sentencing outcomes.       See de 
Jesús, 831 F.3d at 43
.




                                       - 44 -
III. CONCLUSION

            We need go no further. For the reasons elucidated above,

the judgment of the district court is



Affirmed.




                               - 45 -