RECOMMENDED FOR FULL-TEXT PUBLICATION
                              Pursuant to Sixth Circuit Rule 206
                                      File Name: 12a0360p.06

                 UNITED STATES COURT OF APPEALS
                                  FOR THE SIXTH CIRCUIT
                                    _________________


                                                   X
      Plaintiff-Appellee (10-5264 & 10-5432), -
 UNITED STATES OF AMERICA,

           Plaintiff-Appellee/Cross-Appellant --
                          (10-5877 & 10-6084), -
                                                        Nos. 10-5264/5432/5877/6084

                                                    ,
                                                     >
                                                    -
                                                    -
            v.
                                                    -
                                                    -
 LESLIE R. BEALS (10-5264) and PAMELA R.
                                                    -
                        Defendants-Appellants, -
 MILLER (10-5432),

                                                    -
                                                    -
                                                    -
 BOBBY AMBROSE,                                     -
         Defendant-Appellant/Cross-Appellee -
                          (10-5877 & 10-6084). N
                     Appeal from the United States District Court
                 for the Eastern District of Tennessee at Greeneville.
         Nos. 2:08-cr-58; 2:08-cr-39—Robert Leon Jordan, District Judge.
                                   Argued: January 10, 2012
                            Decided and Filed: October 16, 2012
    Before: SILER and GRIFFIN, Circuit Judges; and TARNOW, District Judge.*

                                      _________________

                                            COUNSEL
ARGUED: D. R. Smith, LAW OFFICE OF D.R. SMITH, Johnson City, Tennessee, for
Appellant/Cross-Appellee in 10-5877 and 10-6084. Caryn L. Hebets, UNITED
STATES ATTORNEY’S OFFICE, Johnson City, Tennessee, for Appellee/Cross-
Appellant in 10-5877 and 10-6084. ON BRIEF: James T. Bowman, Johnson City,
Tennessee, for Appellant in 10-5264. Tracy Jackson Smith, LAW OFFICE OF TRACY
JACKSON SMITH, Knoxville, Tennessee, for Appellant in 10-5432. D. R. Smith,
LAW OFFICE OF D.R. SMITH, Johnson City, Tennessee, for Appellant/Cross-Appellee
in cases 10-5877 and 10-6084. Caryn L. Hebets, UNITED STATES ATTORNEY’S


        *
        The Honorable Arthur J. Tarnow, Senior United States District Judge for the Eastern District of
Michigan, sitting by designation.


                                                  1
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                            Page 2


OFFICE, Johnson City, Tennessee, for Appellee in 10-5264 and 10-5432 and for
Appellee/Cross-Appellant in 10-5877 and 10-6084.
       GRIFFIN, J., delivered the opinion of the court, in which SILER, J., joined.
TARNOW, D. J., joined the opinion of the court regarding Beals and Ambrose; and
concurred in the judgment only regarding Miller. TARNOW, D. J. (pp. 33–35),
delivered a separate concurring opinion with regard to appeal 10-5432.
                                   _________________

                                        OPINION
                                   _________________

        GRIFFIN, Circuit Judge. These four consolidated appeals involve an alleged
methamphetamine manufacturing and distribution conspiracy in eastern Tennessee that
involved forty-nine indicted defendants. See 21 U.S.C. §§ 841(a), 846. Defendant
Pamela Miller pleaded guilty and now challenges her sentence. (Appeal No. 10–5432)
The government contends that Miller promised not to appeal her sentence as part of her
agreement to plead guilty. It moves to dismiss her appeal. Defendants Leslie Beals and
Bobby Ambrose chose to go to trial, and a jury convicted them as charged. Beals
appeals his convictions on the ground that the evidence was insufficient. (Appeal No.
10–5264) Ambrose challenges some of his convictions on the same ground and also
claims error in the district court’s denials of his pretrial suppression motion and mid-trial
request for the government to disclose the identity of a confidential informant. (Appeal
No. 10–5877) Finally, the government cross-appeals Ambrose’s sentence, claiming the
Supreme Court’s intervening decision in Abbott v. United States, 

(2010),
renders it unlawful. (Appeal No. 10–6084)

        For the following reasons, we dismiss Miller’s appeal as waived, affirm Beals’s
convictions, vacate Ambrose’s sentence, and remand Ambrose’s case for further
factfinding and resentencing. We address the appeals separately.
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                        Page 3


                          I. Miller’s Appeal (No. 10–5432)

                                           A.

       The government charged Pamela Miller with conspiracy to manufacture 50 or
more grams of methamphetamine and 500 or more grams of a mixture or substance
containing methamphetamine, as well as possession of equipment used to manufacture
methamphetamine. She agreed to plead to the lesser included offense of conspiracy to
manufacture 50 or more grams of a mixture or substance containing methamphetamine
in exchange for the government’s promise to dismiss the possession charge.

       As part of her plea agreement, Miller stipulated that she conspired to
“manufacture approximately 80.43 grams of a mixture and substance containing a
detectable amount of methamphetamine, . . . and that [she] purchased 146.25 grams of
pseudoephedrine which [she] provided to other co-conspirators to manufacture
methamphetamine.” The plea agreement states that “this quantity of pseudoephedrine
converts to 1,462.50 kilograms of marijuana.” The district court accepted Miller’s guilty
plea. It then sentenced her to 120 months’ imprisonment, the bottom end of the
Guidelines range it calculated.

       Miller challenges primarily the district court’s decision at sentencing to use the
marijuana equivalency of the pseudoephedrine she purchased, instead of the quantity of
the mixture and substance containing methamphetamine she conspired to manufacture,
to calculate her Guidelines range. The court’s election to do so increased Miller’s
Guidelines range and ultimate sentence.

                                           B.

       The government has moved to dismiss Miller’s appeal on the ground that she
waived the right to appeal her sentence as part of her plea agreement. We agree and
therefore grant its motion.

       Miller’s plea agreement contains the following provision regarding appeals:
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                         Page 4


       [T]he defendant agrees not to file a direct appeal of the defendant’s
       conviction or sentence except the defendant retains the right to appeal a
       sentence imposed above the sentencing guideline range as determined by
       the district court.

Miller received a within-Guidelines sentence.

       The law in this area is well-settled: “Criminal defendants may waive their right
to appeal as part of a plea agreement so long as the waiver is made knowingly and
voluntarily.” United States v. Swanberg, 

, 625 (6th Cir. 2004). When they
do so, “[o]nly challenges to the validity of the waiver itself will be entertained on
appeal.” United States v. Toth, 

, 377 (6th Cir. 2012). Miller does not
contend that her plea was unknowing or involuntary. She instead argues that the waiver
provision does not cover challenges to the district court’s alleged misapplication of the
Sentencing Guidelines and, alternatively, that the waiver is unenforceable on account of
the government’s breach of the plea agreement. We take the arguments in turn.

                                           1.

       The terms of Miller’s appeal waiver are broad. She waived the right to appeal
any sentence unless it is “above the sentencing guideline range as determined by the
district court.” (Emphasis added.) Reasonably read, this language defers to the district
court’s discretion in calculating Miller’s Guidelines range and permits her to challenge
the resulting sentence only if it exceeds the top end of the range the court calculates.
Miller’s sentence does not exceed the top end of the range as calculated by the district
court. Therefore, the appeal waiver covers her present sentencing challenge and
precludes our review.

       Had Miller wished to preserve a challenge to the district court’s Guidelines
calculation, she certainly could have bargained for it. See, e.g., United States v.
Brandon, 445 F. App’x 845, 846 (6th Cir. 2012) (plea agreement stating that “Defendant
retains his right to directly appeal the Court’s adverse determination of any disputed
guideline issue that was raised at or before the sentencing hearings”); United States v.
Deanda, 450 F. App’x 498, 499 (6th Cir. 2011) (agreement stating that defendant
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                        Page 5


“waives the right to appeal a sentence that is within or below the guideline range as
determined by the Court at sentencing . . . except that the Defendant may appeal on
grounds, preserved at sentencing, that the Court incorrectly determined the guideline
range”); United States v. Vandewege, 433 F. App’x 388, 389 (6th Cir. 2011) (same);
United States v. Flowers, 428 F. App’x 526, 527 (6th Cir. 2011) (same). We must give
effect to the intent of the parties as expressed by the plain language in the plea
agreement. See United States v. Moncivais, 

, 662 (6th Cir. 2007) (“Plea
agreements are to be enforced according to their terms.”).

       Resisting this conclusion, Miller argues that the waiver provision “clearly
presupposes a correct calculation of [her] sentencing guideline range” and thus permits
her challenge. She relies primarily upon United States v. McCoy, 

(1st Cir.
2007), but that case offers her no support. There, as part of his written plea agreement,
the defendant waived his right to appeal any sentence that fell “within the guideline
range.” 

The court held that such language “does not waive the right to appeal
an alleged misapplication of the guidelines.” 

provision is unlike the
one in McCoy. Indeed, McCoy distinguished the language in the provision before it from
language in provisions like Miller’s that waives a defendant’s right to appeal any
sentence imposed within the Guidelines range “as determined by the district court.” 

n.4. Such “[b]roader appeal waivers,” McCoy suggested, could preclude appellate
challenges to the district court’s Guidelines calculation. 

States v. Giganti, 405 F. App’x 31 (6th Cir. 2010), we held that an
appeal waiver that extinguished a defendant’s right to appeal any sentence “within or
below the guideline range as determined by the Court at sentencing”—which is what
Miller’s provision says—precluded any challenge to the district court’s Guidelines
calculation. 

(emphasis added). We found that the waiver provision was “very
different” from the one in McCoy, and we expressly recognized that the discussion in
McCoy regarding alternative waiver language in fact supported a finding of waiver in
the case then before us. 

Circuit reached a similar result in United States
v. Corso, 

(3d Cir. 2008), where it distinguished McCoy and concluded that
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                          Page 6


a provision permitting an appeal only if the sentence “unreasonably exceeds the
guideline range determined by the Court under the Sentencing Guidelines” explicitly
lodges “broad discretion in the District Court to determine the applicable Guidelines
range” and “certainly does not permit an appeal challenging the District Court’s
application of the Guidelines.” 

(emphasis in original). We agree with the
reasoning in Giganti and Corso. Miller’s current challenge to her sentence is plainly
foreclosed by her appeal waiver.

                                           2.

       Miller’s alternative position is that the government’s breach of the plea
agreement frees her from her waiver. According to Miller, the government breached the
agreement when it urged the district court to use pseudoephedrine’s marijuana
equivalency to calculate Miller’s base offense level, despite expressly agreeing in
writing that Miller had conspired to manufacture 80.43 grams of a mixture and substance
containing methamphetamine.

       There was no breach. Miller’s argument depends entirely upon the premise that
the government promised, in exchange for Miller’s promise to plead guilty, either (1) to
ask the district court to determine Miller’s base offense level according to the agreed-
upon quantity of mixture or substance containing methamphetamine; or (2) not to ask
the district court to use pseudoephedrine’s marijuana equivalency in determining the
base offense level. That premise, however, has no factual basis and is foreclosed by the
plea agreement itself, which includes the following relevant provisions:

       The parties agree that the appropriate disposition of this case would be
       the following:
       a)      The Court may impose any lawful term of imprisonment up to the
               statutory maximum . . . .
                                         ***
       No promises have been made by any representative of the United States
       to the defendant as to what the sentence will be in this case. Any
       estimates or predictions made to the defendant by defense counsel or any
       other person regarding the potential sentence in this case are not binding
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                         Page 7


       on the Court. The defendant understands that the sentence in this case
       will be determined by the Court after it receives the pre-sentence report
       from the United States Probation Office and any information presented
       by the parties.

(Emphasis added.)

       Miller points to the statement in her plea agreement that she conspired with
others to “manufacture approximately 80.43 grams of a mixture and substance
containing a detectable amount of methamphetamine.” But the statement is simply
that—a statement of fact; it cannot be reasonably read as a promise by the government
to make (or not make) certain arguments at sentencing. See 

(noting that a plea agreement “must be construed as a reasonable person would interpret
its words”). Furthermore, the statement appears in the section of the plea agreement
supplying the factual basis for the plea and prefaced by the following: “These are the
facts submitted for purposes of the defendant’s guilty plea. . . . Other facts may be
relevant to sentencing. [The parties] retain the right to present additional facts to the
Court to ensure a fair and appropriate sentence in this case.” 

undermines the relevance of the statement regarding the quantity of a mixture or
substance for purposes of sentencing. Finally, any attempt to read the statement as a
promise fails in light of the plea agreement’s integration clause: “[The parties] agree
that . . . any other promises, representations, and statements whether made before,
contemporaneous with, or after this agreement, are null and void.” The government did
not breach the plea agreement.

                                           C.

       Because Miller validly waived her right to challenge her sentence, we grant the
government’s motion to dismiss her appeal.
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                         Page 8


                           II. Beals’s Appeal (No. 10–5264)

                                           A.

       The government charged Leslie Beals with (1) conspiracy to distribute 50 or
more grams of methamphetamine and 500 or more grams of a mixture or substance
containing a detectable amount of methamphetamine, (2) conspiracy to manufacture the
same, and (3) possession of equipment used to manufacture methamphetamine. By way
of five separate indictments, the government alleged that forty-nine defendants were part
of the single drug conspiracy charged in counts one and two. Beals pleaded not guilty
and went to trial. He was tried jointly with co-defendant Bobby Ambrose. The trial
lasted five days.

       The testimony at trial showed that Beals assisted others, primarily co-defendant
Christopher Baucom, who pleaded guilty and testified against Beals, to manufacture and
sell methamphetamine. Beals’s assistance came in the form of supplying Baucom and
others with vast amounts of cold pills containing pseudoephedrine, which is then
extracted and used to create methamphetamine. Beals sometimes helped in extracting
pseudoephedrine from the pills by crushing and placing them in denatured alcohol.
Once the pseudoephedrine separated from the other ingredients in the pill, it was filtered
from the other ingredients and dried. Beals provided other supplies for the cooks as
well, including batteries containing lithium, another essential ingredient used to create
methamphetamine. He also sold the finished product to others. Baucom testified that
Beals helped him cook methamphetamine at least eight to ten times and that each session
produced in excess of fifteen grams of methamphetamine.

       At the close of the evidence, Beals moved for a judgment of acquittal on all three
counts, but the court denied the motion. He then argued to the jury that, although he
may have been involved in multiple conspiracies to manufacture and sell
methamphetamine, the government failed to prove that he engaged in the large, single
conspiracy alleged in the indictment. The jury convicted him on all three counts. Beals
timely appealed.
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                         Page 9


                                           B.

       Beals contends that there was a fatal variance in the proofs on the conspiracy
counts—the indictment alleged a single conspiracy but the evidence proved only the
existence of multiple, smaller ones—and also that the evidence did not prove that he
possessed equipment used to manufacture methamphetamine.               We review these
challenges de novo. United States v. Swafford, 

, 841 (6th Cir. 2008)
(variance); United States v. Fisher, 

, 450 (6th Cir. 2011) (sufficiency of the
evidence).

                                            1.

       The jury convicted Beals of conspiracy to manufacture and distribute 50 or more
grams of methamphetamine and 500 grams or more of a mixture or substance containing
methamphetamine. Beals argues that the government proved the existence of only
multiple, smaller conspiracies, not the larger one he was charged with joining. In his
view, each cooking session was a separate conspiracy that ended after the cook.

       A variance occurs when “the charging terms of the indictment are unchanged, but
the evidence at trial proves facts materially different from those alleged in the
indictment.” 

(internal quotation marks omitted). In a
conspiracy prosecution, a variance demands reversal only if (1) “the indictment alleged
one conspiracy, but the evidence can reasonably be construed only as supporting a
finding of multiple conspiracies,” and (2) the variance prejudiced the defendant. United
States v. Williams, 

, 423 (6th Cir. 2010). Whether the government has
proved one or only multiple conspiracies is a question of fact considered on appeal in
the light most favorable to the government. United States v. Smith, 

, 652
(6th Cir. 2003).

       To establish a drug conspiracy, the government must prove an agreement to
violate the drug laws—i.e., to manufacture or distribute drugs—and that each conspirator
knew of, intended to join, and participated in the conspiracy. United States v. Walls,

, 967 (6th Cir. 2002). Its burden is to prove that “each alleged member
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                        Page 10


agreed to participate in what he knew to be a collective venture directed toward a
common goal.” United States v. Warner, 

, 549 (6th Cir. 1982) (quotation
marks and citation omitted). A tacit or material understanding among parties to a
conspiracy is sufficient to establish agreement. 

not be proved with
direct evidence; it can be inferred from circumstantial evidence reasonably interpreted
as participation in a common plan. 

conspiracy is not converted to multiple conspiracies simply because
it can be subdivided, or because there are changes in the individuals involved or the roles
that they play in the conspiracy.” 

. Nor does conversion take
place “simply because each member of the conspiracy did not know every other member,
or because each member did not know of or become involved in all of the activities in
furtherance of the conspiracy.” 

. In determining the number of
conspiracies, we consider whether there was a common goal among the participants, the
nature of the scheme, and the extent of overlap in the participants’ various dealings.

.

       When viewed in the light most favorable to the government, the evidence at
Beals’s trial was sufficient to permit the jury to find the existence of a single drug
conspiracy. First, the government successfully proved a common goal among the
charged co-conspirators: the production of a steady supply of methamphetamine in
order to satisfy their shared addiction. To achieve this goal, the co-conspirators both
taught one another how to make methamphetamine and helped procure the ingredients
and supplies needed to make it. The goal was shared by all participants, each of whom
was aware to some extent that the conspiracy was larger than simply his or her
individual interactions with others. The participants generally agreed that if suppliers
provided pills and other materials to the cooks, the cooks would use them to make and
share methamphetamine so all could satisfy their addictions.

       The nature of the scheme also suggests a single conspiracy. It revolved around
a number of individuals, including Donald Huffman, Bobby Ambrose, Christopher
Baucom, and Mike Holtsclaw, who knew how to cook methamphetamine and did so
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                         Page 11


regularly. The cooks knew that each other cooked and sometimes assisted one another
in doing so. But the cooks could not make the drug without the help of others. As
Baucom explained, making methamphetamine requires a lot of pseudoephedrine. And
although the drug is contained in over-the-counter cold medicine, one person can only
buy so many pills at a time, usually just one box, to avoid tipping off law enforcement.
Therefore, cooks depend on other addicts for pills. Addicts trade cold pills for
methamphetamine and then consume what they need and sell the remainder for cash or
more pills. The cooks and suppliers did not deviate from this scheme for satisfying their
addictions. No one, for instance, rather than buying cold pills from a local drug store,
imported large quantities of methamphetamine or its precursors from another state or
country and sold them to addicts in the area. The pills were purchased locally and
provided to the same handful of cooks, all of whom lived in the area. The nature of the
scheme suggests a single conspiracy. Cf. 

–53 (finding it relevant
that each transaction in the single conspiracy “followed an identical modus operandi”).

        Finally, there was substantial overlap in the participants of the cooking sessions.
See United States v. Mitchell, 

, 770 (5th Cir. 2007) (“The more
interconnected the various relationships are, the more likely there is a single conspiracy.”
(quotation marks omitted)). Those who knew how to cook watched and learned from
one another. For example, Huffman watched Holtsclaw cook and discussed with
Ambrose various methods for making the drug. Ambrose also watched Huffman on
occasion and once helped him clean up after a cook. Baucom provided Huffman with
pills and testified that he worked with Ambrose, Holtsclaw, and Huffman, among others.
Holtsclaw once helped Huffman steal a tank of anhydrous ammonia, another necessary
ingredient in making methamphetamine, from a beverage store.

        There also was overlap and cooperation among those who supplied pills. Cooks
would not go through the trouble of making the drug if only a small amount would be
produced. Baucom testified that cooking up only one box worth of pills was not worth
the effort and was therefore rarely done. Huffman said he usually tried to cook ten boxes
at a time. Therefore, pill suppliers worked with each other to provide the necessary
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                       Page 12


amount of pseudoephedrine to make a fruitful cooking session. Similarly, cooks did not
always receive pills from the same people; there was significant intermingling. For
instance, Christy Gray routinely gave pills to “a lot of different people,” including
Huffman and Holtsclaw. Jacqueline Wigand exchanged pills for methamphetamine with
both Holtsclaw and Ambrose, usually through an intermediary. Jason Woody gave
Baucom pills in exchange for methamphetamine. One time, he went with Baucom to
Ambrose’s garage to exchange pills for meth. Baucom introduced Woody to Ambrose
for the purpose of giving Woody direct access to Ambrose so he did not have to go
through Baucom. Woody later offered his home as a place where he, Baucom, and
Ambrose could cook batches of meth. Daniel Burleson gave pills to Huffman, Baucom,
and Sean Queen, another cook, in exchange for the finished product. Lori Collins traded
pills with “multiple people,” including Holtsclaw and Baucom. Lesia Bradley developed
a recipe for manufacturing anhydrous ammonia and shared it with Baucom. She cooked
many times with Huffman, who is also her husband, for many years and witnessed him
cook with Holtsclaw and Baucom. She sometimes attended gatherings and supervised
other cooks, including Holtsclaw, Baucom, and Douglas Morrell. She attended one cook
at Beals’s home where she provided anhydrous ammonia and helped the cooks start to
process pills. Baucom, Woody, and Beals were present. She also knew Ambrose, and
the two socialized together, one time getting high with methamphetamine that Ambrose
had supplied. This small sample is representative of the overlapping relationships shared
among cooks and pill suppliers.

       Based upon the common goal shared by the co-conspirators, the singular nature
of the scheme used to achieve that goal, and the substantial overlap in participants, the
evidence “does not exclude the possibility” that a single drug conspiracy existed. United
States v. Caver, 

, 236 (6th Cir. 2006). Beals’s alternative interpretation of
the evidence is a nice one that he had the opportunity to argue to the jury in accordance
with a proper instruction, but not one that the Due Process Clause required the jury to
accept based on the evidence. And Beals’s further point that not all co-conspirators
knew each another or attended the same cooking sessions similarly did not preclude
finding a single conspiracy. See 

; see also United States v.
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                       Page 13


Rodriguez-Ramos, 

, 362 (8th Cir. 2011) (“One conspiracy may exist despite
the involvement of multiple groups and the performance of separate acts.” (quotation
marks omitted)). The evidence permitted the jury also to conclude that Beals joined this
single conspiracy.

       Swafford is not to the contrary. There, the defendant owned a home-and-garden
store out of which he sold iodine, an essential ingredient in making 

. During the time charged in the indictment, the defendant sold large
quantities of the ingredient to more than twenty customers, all of whom (except for two)
had absolutely no connection with one another. The lack of connection meant that they
shared no common goal, precluding a finding of a single conspiracy that involved the
defendant and all the customers. 

The same problem does not exist here. As
already discussed, there were extensive connections between cooks and the suppliers,
who all shared a common goal of manufacturing the drug for the primary purpose of
satisfying their addictions.

                                           2.

       The jury also convicted Beals of possessing equipment used to manufacture
methamphetamine, in violation of 21 U.S.C. § 843(a)(6). Beals contends that the only
evidence to support this conviction is the existence of a plastic cooler, hair dryer, and
funnels found behind his house. He claims a lack of evidence that these items were
actually used to cook methamphetamine or that the equipment had any connection to
him. The government seems to agree and points instead to the evidence showing that
Beals possessed lithium batteries and high quantities of cold pills containing
pseudoephedrine, both of which are used to manufacture methamphetamine. The
evidence was sufficient to find Beals guilty of this charge.

                                           C.

       For these reasons, we affirm Beals’s convictions.
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                        Page 14


                         III. Ambrose’s Appeal (No. 10–5877)

                                            A.

       Bobby Ambrose was charged with the following offenses: (1) conspiracy to
distribute 50 or more grams of methamphetamine and 500 or more grams of a mixture
or substance containing a detectable amount of methamphetamine; (2) conspiracy to
manufacture the same; (3) possession of equipment used to manufacture
methamphetamine; (4) maintaining a place for the purpose of manufacturing,
distributing, or using methamphetamine; (5) possession of a firearm in furtherance of a
drug trafficking crime; and (6) being a felon in possession of a firearm. He pleaded not
guilty and was tried jointly with co-defendant Leslie Beals. A jury convicted him on all
counts. He appeals and raises four challenges.

                                            B.

       Some of the evidence introduced against Ambrose at trial—notably the gun that
gave rise to the two gun convictions—was seized from his garage during the execution
of a search warrant issued by a state-court judge and executed entirely by state officers.
Ambrose moved to suppress this evidence, but the district court, upon the
recommendation of a magistrate after an evidentiary hearing, denied the motion.

                                            1.

       During the evening hours of April 22, 2008, Michael Hensley, an officer with the
Unicoi County Sheriff’s Department, presented to Tennessee Criminal Court Judge
Robert Cupp an affidavit in support of an application for a search warrant. Hensley
swore in the affidavit that a reliable confidential informant told him he had recently seen
the following contraband in Ambrose’s garage, located at 106 Union Street in Erwin,
Tennessee: four to five grams of methamphetamine, six grams of marijuana, four Xanax
pills, a handgun, glass smoking pipes, and materials for making glass pipes. Hensley
swore also that a records check of ephedrine purchases from local pharmacies revealed
that Ambrose and others associated with him had recently purchased at least ten boxes
of ephedrine, a key ingredient in making methamphetamine. The associates had
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                         Page 15


apparently brought Ambrose the ephedrine for the purpose of manufacturing
methamphetamine. Based on this information, Judge Cupp issued a warrant for the
search of the “entire garage area of [106] Union Street and [the] vehicles inside.”
Although Hensley presented three copies of his affidavit and warrant for signature, Judge
Cupp inadvertently signed and dated only one, which he retained as part of his official
records in accordance with state rules. See Tenn. R. Crim. P. 41(d). Hensley left Judge
Cupp’s home with the unsigned copies, unaware that they were not signed.

       The structure located at 106 Union Street is a large building that at an earlier time
contained only a garage. Later, however, a section of the building was partitioned off,
and the enclosed section now contains six to eight small, single-room apartments
accessed by a separate entrance bearing an address of 108 Union Street. The portion of
the building designated “106 Union Street” contains three areas: a garage, an apartment
where Ambrose and his wife and child live, and an upstairs living area where Ambrose’s
mother lives. When the officers arrived, they were unaware of the layout inside
106 Union Street. From outside the front of the building one sees three doors: a large
garage door, a pedestrian door labeled “106,” and a third labeled “108.” The door
labeled “106” opens into a hallway that contains two interior doors—one that opens into
the garage and another that opens into Ambrose’s apartment. A set of stairs in the
hallway leads to an upstairs room where Ambrose’s mother resided. A door in an alley
behind the building opens directly into Ambrose’s apartment.

       State officers executed the search warrant around midnight, shortly after Judge
Cupp issued the warrant. A group went to the front door while others went to the back.
The officers at the front door arrested Ambrose in the hallway immediately after
entering. The group in the back knocked on the apartment door and announced that they
had a search warrant. Ambrose’s wife answered, and the officers repeated that they had
a warrant to search the garage. They entered and proceeded through the apartment to the
hallway that leads to the garage. Two officers went upstairs to the area where
Ambrose’s mother lived to briefly look for persons before meeting the remaining officers
in the garage to assist with the search.
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                        Page 16


       During the search of the garage, officers found and seized contraband, including
a handgun and coffee filters containing trace amounts of ephedrine, an essential
ingredient in creating methamphetamine. Sometime during the night, officers briefly
entered an apartment at the 108 Union Street address with the assistance of Ambrose’s
mother, who had a key. Their informant had told them the person living there may have
overdosed on methamphetamine and be in need of emergency medical assistance. They
knocked on what they believed was the person’s door, but no one answered. Upon
hearing the commotion, a neighbor opened his door and told the officers he had not seen
the occupant in a few days. The officers relayed their concern to Ambrose’s mother,
who retrieved a key and let the officers in. No one was there, so the officers left. One
officer also briefly looked in a nightstand in Ambrose’s apartment for a key to a vending
machine in the garage. No contraband was found or seized from any area other than the
garage. Evidence seized from the garage, including the handgun, was offered against
Ambrose at trial.

                                            2.

       Ambrose makes three suppression-related arguments on appeal: (1) the search
warrant’s deficiency under state law rendered the search warrantless, in violation of the
Fourth Amendment; (2) the warrant’s affidavit contained false information critical to the
finding of probable cause; and (3) all seized evidence should have been suppressed
because the officers searched in places not authorized by the warrant. When reviewing
a district court’s ruling on a motion to suppress, we review its factual findings for clear
error and its legal conclusions de novo. United States v. Archibald, 

, 294
(6th Cir. 2009). We may affirm the ruling on any ground supported by the record.
United States v. Gill, 

, 609 (6th Cir. 2012).

                                            a.

       Tennessee Rule of Criminal Procedure 41(d) requires that a magistrate issuing
a search warrant prepare an original and two exact copies of the warrant. There is no
dispute here that the search warrant did not comply with this requirement, as only one
copy bore Judge Cupp’s signature. The government concedes that this procedural defect
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                          Page 17


would require suppression in a state prosecution. See State v. Steele, 

,
319 (Tenn. Crim. App. 1994). We consider whether suppression is similarly required
in a prosecution in federal court.

        “The commonly-held position is that federal, not state, law governs the question
of the validity of a [state-issued] search warrant in a federal criminal proceeding.”
United States v. Shields, 

, 945 (6th Cir. 1992); accord United States v.
Clyburn, 

, 614 (4th Cir. 1994) (“[T]he validity of a search warrant obtained
by state officers is to be tested by the requirements of the Fourth Amendment of the U.S.
Constitution, not by state law standards, when the admissibility of evidence in federal
court is at issue.”). Similarly, “in federal court, [the exclusionary rule] only requires the
court to exclude evidence seized in violation of the Federal Constitution.” United States
v. Wright, 

, 1434 (6th Cir. 1994). That is because the exclusionary rule
“emanates from the Fourth Amendment, not state law[.]” 

states are free
to impose rules for searches and seizures that are more restrictive than the Fourth
Amendment, those rules will not be enforced in a federal criminal proceeding. 

determining whether evidence obtained solely by state officers is
admissible in federal court in the first instance, it is usually irrelevant whether a state
rule of criminal procedure was violated.” United States v. Maholy, 

, 721 (8th
Cir. 1993); see also Virginia v. Moore, 

, 178 (2008) (noting that “it is not
the province of the Fourth Amendment to enforce state law”). This rule “promotes
uniformity in federal prosecutions.” 

.

        Although no court to our knowledge has before addressed the precise question
raised here, we find that the answer is squarely governed by the rule that only the Fourth
Amendment (to the exclusion of state law) applies in federal prosecutions involving
evidence seized by state officials. So long as the Fourth Amendment is satisfied, there
is no basis for suppression. Accordingly, we turn to the Fourth Amendment, which
requires “only three things” with respect to search warrants. Dalia v. United States,

, 255 (1979). The first is that they be issued only by “neutral and detached”
magistrates “capable of determining whether probable cause exists for the requested
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                         Page 18


arrest or search.” Shadwick v. City of Tampa, 

, 350 (1972); see Johnson v.
United States, 

, 14 (1948) (“[The Fourth Amendment’s] protection consists
in requiring that . . . inferences [of probable cause] be drawn by a neutral and detached
magistrate instead of being judged by the officer engaged in the often competitive
enterprise of ferreting out crime.”). There is no dispute that Judge Cupp satisfied these
criteria when he authorized the search of Ambrose’s garage.

        The second requirement is that search warrants issue only upon a finding of
“probable cause.” U.S. Const. amend. IV. We address this issue separately below and
assume for present purposes that it was satisfied. The final requirement is that search
warrants “particularly describ[e] the place to be searched, and the . . . things to be
seized.” Id.; see Maryland v. Garrison, 

, 84–85 (1987). There is similarly
no dispute that the warrant met this requirement. Because the Fourth Amendment
requirements for warrants were met in this case, the district court properly rejected
Ambrose’s request for suppression on the basis of an invalid search warrant.

        Ambrose seeks to transform the warrant’s defect under state law into a
constitutional violation by arguing that a state judge who does not comply with state
requirements when approving a search warrant never “issues” the warrant, thereby
making any resulting search warrantless and therefore unconstitutional. A similar
situation arises when a state magistrate, in violation of state rules, relies upon unwritten
(though sworn) statements from an officer to find probable cause for a search warrant.
Suppression in such instances is not required in federal proceedings (for there is no
Fourth Amendment violation) even though it would be required were the defendant
being prosecuted in state court, solely on account of the state-law violation. See United
States v. Parker, 4 F. App’x 282, 284 & n.2 (6th Cir. 2001); 

–46;
accord 

–17; see also 

(holding that an
officer’s noncompliance with a state rule of procedure requiring “reasonable cause” for
a nighttime search warrant is “irrelevant to determining, at least in the first instance,
whether the fruits of the search are admissible in federal court”). This reasoning applies
with the same force to noncompliance with a state rule that requires a magistrate to sign
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                         Page 19


a certain number of copies of the warrant—it matters not in a federal proceeding; the
warrant is not any less “issued.” Had Judge Cupp failed to sign any copy of the warrant,
it might plausibly be maintained that a warrant never issued in the first place as a matter
of fact. But that is not what happened here. Judge Cupp’s signature on one copy of the
warrant was sufficient to satisfy the Fourth Amendment.

        Nor is it problematic under the Fourth Amendment that the officers executed an
unsigned copy of the warrant. Cf. United States v. Lipford, 

, 269–70 (4th
Cir. 2000) (finding no Fourth Amendment violation where officers presented defendant
with unsigned copy of search warrant before searching his home). Doing so did not
make the warrant any less “issued.”

        Our recent decision in United States v. Master, 

(6th Cir. 2010),
upon which Ambrose relies, does not require otherwise. There, the government
conceded that, as a matter of state statutory law, the state judge lacked authority to issue
the search warrant, which was for a residence in a neighboring county over which the
judge did not preside. 

We held the warrant void ab initio, explaining that
the Fourth Amendment permits warrants to issue only after a probable-cause
determination made by a neutral and detached “magistrate,” a term the Supreme Court
has permitted the States to define. “The qualifications of a magistrate,” we noted, “are
therefore inextricably intertwined with state law,” and “[s]tate law determines what
person is allowed to approve what warrant.” 

We reasoned that if the States
get to decide who has authority to issue warrants (provided the persons are neutral and
detached and capable of determining whether probable cause exists), then they are
entitled also to define the scope of that authority in any way they wish. Because the
magistrate in Master lacked authority under state law to issue a warrant for a search in
a different county, the warrant was never issued by a “magistrate,” in violation of the
Fourth Amendment. 

See also United States v. Scott, 

, 515 & n.2
(6th Cir. 2001) (search warrant signed by a retired state judge “wholly without legal
authority to issue a warrant” under state law was void ab initio), overruled on other
grounds by 

; United States v. Bennett, 

, 636–37
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                        Page 20


(6th Cir. 1999) (search warrant issued by court clerk authorized by state law to do so was
valid under the Fourth Amendment).

       Unlike in Master, however, the Fourth Amendment question here is not tied to
a question of state law. Judge Cupp had authority under state law to issue search
warrants, and his failure to sign two copies of the search warrant did not in any way
deprive him of that authority.

       United States v. Bennett, 

(6th Cir. 1999), also does not change
matters. At issue there was a search warrant issued by a state court clerk while the
judges were absent. State law authorized the clerk to issue warrants in such instances.
The defendant claimed the warrant was invalid due to noncompliance with Federal Rule
of Criminal Procedure 41, which allows only judges to issue warrants. The contention
prompted us to reaffirm that “the validity of a search warrant obtained by state officers
for seizure of evidence ultimately used in a federal prosecution turns only on
constitutional issues” (and not federal statutory issues), 

and we rejected the
defendant’s argument. We also stated, perhaps inartfully, that “the validity of the search
warrant in this case must be tested pursuant to Kentucky criminal procedural
requirements and the Constitution.” 

Ambrose understandably seeks refuge
in our statement regarding the relevance of state law to the question of a warrant’s
validity for purposes of federal suppression proceedings. These two statements appear
to be in conflict—the first says to consider only federal law, the second says to look also
at state law. Upon a closer reading, however, they are entirely consonant.

       Bennett asked whether the court clerk had authority to issue the search warrant.
The answer to this question—the very one involved in Master, supra—turned on a
matter of state law and therefore required us to consider it to answer the constitutional
question. Accordingly, the statements, both correct, are consistent in the following way:
the validity of a state warrant in federal proceedings does indeed turn only on
constitutional issues, but because the constitutional question involved there—whether
the court clerk was a neutral and detached magistrate, as required by the Fourth
Amendment—depended on state law, we had to consider state procedural requirements
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                                 Page 21


in order to reach an answer. Our statement in Bennett regarding the consideration of
state law in a federal suppression proceeding is irrelevant here, for the answer to the
Fourth Amendment question does not depend upon state law.

                                                b.

        Next, Ambrose contends that the search warrant included a false statement that
was necessary to establish probable cause for the search.1 The targeted statement
concerns a check of pharmacy records purportedly performed by Major Hensley that
apparently revealed that Ambrose had purchased at least ten boxes of ephedrine within
the past seven days. But even if we excise this allegedly false statement from Hensley’s
affidavit, we are still left with enough information to generate probable cause for the
search. See Franks v. Delaware, 

, 156 (1978). The following facts gave
the state judge a “substantial basis” for finding “a fair probability that contraband or
evidence of a crime [would] be found” in the garage, Illinois v. Gates, 

,
238–39 (1983): (1) the confidential informant recently saw various illegal drugs in
specific amounts in the garage; (2) Ambrose’s associates recently brought him boxes of
ephedrine with the purpose of manufacturing methamphetamine; (3) the informant saw
glass smoking pipes and materials for making these pipes in the garage; (4) the
informant saw a handgun in the garage; and (5) Ambrose was a felon and therefore not
permitted to possess a firearm.

                                                c.

        In his final challenge to the search, Ambrose contends that suppression of all the
seized evidence was necessary because the authorized search of the garage devolved into
an unlawful general search of the entire building, including Ambrose’s apartment, his
mother’s apartment, and an apartment at the 108 Union Street address. See United States
v. Lambert, 

, 93 (6th Cir. 1985) (“A flagrant disregard for the limitations of
a search warrant might make an otherwise valid search an impermissible general search


        1
          The government contends that Ambrose forfeited this argument by not objecting to the
magistrate’s report and recommendation. See United States v. Walters, 

, 949–50 (6th Cir.
1981). It is mistaken, because Ambrose did object. See R.185 at 5–6.
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                        Page 22


requiring the suppression of all evidence seized during the search.”).           Blanket
suppression, though an extreme remedy for a Fourth Amendment violation, is
nonetheless warranted when officers “flagrant[ly] disregard” the limitations on a search
warrant. 

is appropriate where officers “‘exceed[] the scope of the
warrant in the places searched’ (rather than the items seized).” United States v. Garcia,

, 507 (6th Cir. 2007) (quoting Waller v. Georgia, 

, 43 n.3
(1984)). If the search of places not authorized by a warrant satisfies an exception to the
warrant requirement, however, there is no violation and no basis for blanket suppression.
See 

the test is “whether [the officers’] search unreasonably exceeded
the scope of the warrant”). Although the district court acknowledged these rules and
addressed some of Ambrose’s allegations on this front, it did not address all of them.
It thereby left us with an incomplete set of findings that must be supplemented.

       Officers briefly looked in an upstairs living area where Ambrose’s mother
resides. They did so not for the purpose of finding contraband, but rather to ensure their
safety from persons who might be hiding therein and wanting to attack them during the
search of the garage. When the officers arrived at the building, they learned that the
address that contained the garage and Ambrose’s apartment also housed an upstairs room
that connected directly to the garage by a hallway. Ambrose’s wife told them there was
another person upstairs. The officers already believed that drugs and at least one gun
were inside the building. This knowledge allowed them to perform a brief protective
sweep of the upstairs living area. Cf. Maryland v. Buie, 

, 334–35 (1990);
United States v. Taylor, 

, 410 (6th Cir. 2012).

       Officers also entered and briefly looked inside a non-adjoining apartment at the
108 Union Street address upon their belief that the occupant might be in need of
immediate medical attention due to a possible drug overdose. There is absolutely no
indication, however, that Ambrose had any expectation of privacy (let alone a reasonable
one) in an apartment being rented by another individual. Accordingly, Ambrose lacks
the ability to challenge the officers’ brief entry into the room. See Rakas v. Illinois,
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                        Page 23

, 140 (1978); United States v. King, 

, 743–44, 751 (6th Cir.
2000).

         During the search of the garage, officers observed a locked vending machine that
they wished to open and search. Rather than destroy the machine, they asked Ambrose
whether he had a key to it. He responded by giving the officers consent to look for the
key in his vehicle and in a nightstand in his apartment. An officer went to the apartment
and advised Mrs. Ambrose of her husband’s consent and looked inside a nightstand for
the key with her assistance (and without any objection). The district court’s finding that
Ambrose gave consent to this limited search of his nightstand is not clearly erroneous.
See United States v. Collins, 

, 701–02 (6th Cir. 2012).

         Three other aspects of the search may be more troublesome. We say “may”
because the district court did not fully address them, so we lack the findings necessary
to determine whether blanket suppression is warranted. They all involve the entry and
search of Ambrose’s apartment apart from the nightstand search. First, officers testified
that when they knocked on Ambrose’s apartment door in their attempt to secure consent
to search the garage, R.176 at 186–87, Mrs. Ambrose opened it and freely let them in.
R.176 at 43 (“[W]e asked if we could come in, she invited us in.”), 65 (“I told her who
we were, identified ourselves, told her why we were there. She invited us in, told us to
come in[.]”). The officers then walked through the apartment and into the hallway that
leads to the garage. 

According to Mrs. Ambrose, the officers entered her
apartment without asking. 

In fact, she asked to get dressed before they came
in, but the officers said “no,” pushed open the door, and came in anyway. 

She said she never invited them in or otherwise gave consent for them to enter. 

The district court did not address this entry, so it never determined which
version of the facts to believe.

         Second, Major Hensley and Ronnie Adkins, Chief Investigator for the Unicoi
County Sheriff’s Department, both testified that they searched Ambrose’s apartment at
his wife’s request. 

51, 69–70. According to both officers, when they
explained to Mrs. Ambrose the basis for their search of the garage, she became
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                                         Page 24


concerned for her own and her young child’s safety and asked the officers to “look
around” her apartment for toxic items related to methamphetamine. They did so and
found nothing of concern. 

flatly denies asking officers to search her
apartment. 

113–14. This dueling testimony was never resolved by the district
court, so there is no finding whether or not Mrs. Ambrose consented to the search of the
apartment.2

         Finally, Ambrose’s mother and sister testified that they watched officers search
Ambrose’s apartment after Mrs. Ambrose left to take her son to the hospital. 

124–25, 131. His mother saw officers take the mattress off the bed and
rummage through dresser drawers. 

Mrs. Ambrose corroborated this
testimony, stating that it appeared her apartment had been thoroughly searched—her
mattress was out of place, clothes were on the floor, and dresser drawers were left open.

The officers, however, testified to the contrary. 

(Q. Okay. You did
not search that apartment where the young lady was? A. Only the area that she
requested.”). This second alleged search of the apartment also was not addressed below.

         In the absence of necessary findings, a remand is required for the limited purpose
of the district court making further findings on these unresolved matters regarding
Ambrose’s apartment (initial entry, search allegedly at Mrs. Ambrose’s request, second
search in Mrs. Ambrose’s absence). We nevertheless will address the remaining issues
raised in Ambrose’s appeal and the government’s cross-appeal and will assume for such
purposes that the search did not unreasonably exceed the scope of the warrant. In the
event the district court determines the officers exceeded the warrant’s scope, it should
determine whether blanket suppression is warranted and, if so, how suppressing all of
the evidence affects Ambrose’s convictions and sentence. Either party may then appeal
from the new judgment.


         2
          The district court sidestepped the issue of consent by finding that the officers entered the
apartment only for the purpose of looking for other persons and thus never truly searched the apartment.
But no officer testified that they swept the apartment for persons. Rather, they testified that they searched
the apartment for methamphetamine-related materials and did so only at Mrs. Ambrose’s request. R.176
at 46–47, 67, 69–70, 71. Officer Ronnie Adkins said he briefly looked in an attic area inside the apartment
to make sure no one was hiding there. But that was only after he and Hensley searched the apartment for
methamphetamine. 

Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                      Page 25


                                          C.

       In his next claim of error, Ambrose contends that the district court erred by not
ordering the government to disclose the identity of a confidential informant whose
statements to police gave rise to the search of Ambrose’s garage. The following
exchange took place between Ambrose’s counsel and an investigating officer:

       Q. Now you indicated that an informant had told you that there was a
       pistol in that garage, right?
       A. Yes, Sir.
       Q. Who is that informant?
       MS. HEBETS: Objection, Your Honor, as to relevance.
       Q. Your Honor, I may want to call that informant. I don’t think it’s
       irrelevant at all.
       MS. HEBETS: Your Honor, I think Mr. Smith needs to lay more
       groundwork if he wants to call that witness. I’m not sure what difference
       it makes. A weapon was found in the garage.
       Q. Your Honor, as the Court knows, during the course of suppression
       hearings and things like that an informant is not disclosed. Now we’re
       talking about permitting hearsay evidence of an informant and not
       permitting me to know who that informant is and to call them. I’d ask
       again to ask the Court to direct him to tell us who his informant was.
       THE COURT: Well, at this point the question is, the informant had
       reported that the gun was located there?
       Q. Yes, Sir.
       THE COURT: And the Sheriff found the gun there?
       Q. That’s right.
       THE COURT: Alright. Let’s leave it at that.
       Q. Did your informant ever describe to you what type of pistol?
       A. He did, yes.
       Q. Okay. And what did your informant tell you?
       MS. HEBETS: Objection, hearsay, relevance.
       THE COURT: (INAUDIBLE) the informant.
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                         Page 26


        Q. Your Honor, I’d like to have the informant’s name.
        THE COURT: I don’t believe that it’s necessary.
        Q. Would the Court like me to move on, Your Honor?
        THE COURT: Yes.

        In Roviaro v. United States, 

(1957), the Supreme Court recognized
the government’s limited privilege to “withhold from disclosure the identity of persons
who furnish information of violations of law to officers charged with enforcement of that
law.” 

However, “[w]here the disclosure of an informer’s identity, or of the
contents of his communication, is relevant and helpful to the defense of an accused, or
is essential to a fair determination of a cause, the privilege must give way.” 

In making the determination, trial courts must balance the public’s interest in protecting
the flow of information against the defendant’s right to prepare a defense. “Whether a
proper balance renders nondisclosure erroneous must depend on the particular
circumstances of each case,” including, among other relevant factors, “the crime
charged, the possible defenses, [and] the possible significance of the informer’s
testimony[.]” 

We review a district court’s decision on the matter for an abuse
of discretion. United States v. Jenkins, 

, 1341 (6th Cir. 1993).

        The district court was within its discretion to allow the government to withhold
the identity of its confidential informant. Ambrose failed to show that disclosure was
“essential to a fair trial.” United States v. Moore, 

, 381 (6th Cir. 1992).
Indeed, Ambrose has not demonstrated how disclosure would have assisted him in any
way. He attempts to compare his situation to Roviaro, where the Supreme Court found
reversible error in not ordering disclosure. The defendant in that case was charged with
facilitating the transportation of drugs while knowing they were imported illegally.

. An informant drove to a location and was later met by the
defendant, who got into the car before the two drove off. The car later stopped, and the
defendant got out, retrieved a small package from behind a tree, gave it to the informant,
and walked away. 

The Court found the charged offense “so closely related to
[the informant] as to make his identity and testimony highly material” and potentially
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                         Page 27


helpful to the defense. 

Central to the Court’s decision was that the statute
did not proscribe mere drug possession, and that the only material witness, apart from
the defendant, was the informant, who was in the car with the defendant and may have
disputed testimony from the government agents who witnessed the transaction from a
distance. The informant might have established entrapment or the defendant’s potential
lack of knowledge regarding the package’s contents. 

          Here, by contrast, the only role the confidential informant played was supplying
reliable information to police that led to a fruitful search. The informant did not
orchestrate or involve himself in any controlled methamphetamine purchases, supply
Ambrose with pseudoephedrine, or sell or lend Ambrose the handgun later found in the
garage.     The informant helped orchestrate the search that led to discovery of
incriminating evidence, not the crimes themselves. Accordingly, the informant could
not testify to any relevant fact, and the district court was therefore within its discretion
not to order disclosure.

                                            D.

          Finally, Ambrose challenges the sufficiency of the evidence on his conspiracy
and firearm convictions.

                                             1.

          With respect to his challenge to the drug-conspiracy convictions, Ambrose makes
the same arguments Beals made regarding single-versus-multiple conspiracies. For the
reasons stated in our rejection of Beals’s challenge, the evidence permitted the jury to
find the existence of the single conspiracy alleged in the indictment and that Ambrose
joined this conspiracy.

                                             2.

          Ambrose also challenges the sufficiency of the evidence that he possessed a
firearm in furtherance of a drug trafficking crime. See 18 U.S.C. § 924(c). Specifically,
he argues that the evidence is insufficient with respect to the “in furtherance of” element
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                       Page 28


of the offense, which requires that the firearm be possessed to “advance, promote, or
facilitate” the underlying criminal activity. United States v. Paige, 

, 609
(6th Cir. 2006).

       “[T]he possession of a firearm on the same premises as a drug transaction would
not, without a showing of a connection between the two, sustain a § 924(c) conviction.”
United States v. Mackey, 

, 462 (6th Cir. 2001). “In order for the possession
to be in furtherance of a drug crime, the firearm must be strategically located so that it
is quickly and easily available for use.” 

a wall-mounted antique or
an unloaded hunting rifle locked in a cupboard[,]” for instance, would not satisfy the
statute. 

in Mackey showed an illegally possessed and loaded short-
barreled shotgun located in the living room of a crack house. It was easily accessible to
the defendant and was placed next to drug scales and razor blades. The defendant was
arrested near the gun and was in possession of cocaine and a large sum of cash. We
found that a jury could find that the firearm’s purpose was to “provide defense or
deterrence in furtherance of the drug trafficking for which the defendant was arrested.”

see also 

–10 (evidence sufficient where two loaded
guns were found under a couch cushion in a residence where crack was being sold
throughout the day and night and where officers found crack, $900 cash, and digital
scales dusted in cocaine residue).

       Here, the evidence was sufficient for a jury to conclude that Ambrose possessed
the .22-caliber handgun in furtherance of a drug trafficking crime. When officers
searched his garage, they found the loaded handgun wrapped in a cloth sitting on a shelf
in the open. Although Ambrose’s father testified that he owned the gun, ownership is
different from possession—one can possess a gun without owning it. Ambrose worked
daily in the garage, a place where others met him on occasion to exchange drugs and
drug-making materials. The evidence also showed that the garage was used as a “pill-
washing station,” i.e., a location used in the early stages of making methamphetamine
to separate pseudoephedrine from the remaining substances in cold-medicine pills.
Officers found wet coffee filters containing ephedrine residue in the trash can in the
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                         Page 29


garage during the search. Although Ambrose’s father testified that he put the gun on the
garage shelf with the intent of repainting it at some point but never got around to it, that
does not reasonably explain why the gun was loaded when it was found. Nor was the
jury required to believe Ambrose’s father’s testimony. Furthermore, Baucom testified
that Ambrose used a gun (though not necessarily this gun) in the past to rob him of a
gun, cash, and drug-making materials. He also testified that he bought “a couple” of
guns from Ambrose in the past. The jury was permitted to use this evidence to conclude
that Ambrose used guns to “advance, promote, or facilitate” his drug-trafficking
enterprise, increasing the likelihood that the handgun found in the garage was used in
the same manner.

                                            E.

         For these reasons, we affirm Ambrose’s convictions on the assumption that the
evidence seized from his garage was properly admitted at trial. We remand the matter
to the district court for the purpose of making the necessary factual findings identified
above.

                    IV. Government’s Cross-Appeal (No. 10–6084)

         The government appeals Ambrose’s sentence, arguing that it has since become
unlawful in light of an intervening Supreme Court case decided during this appeal.

         Ambrose was sentenced to 168 months’ imprisonment, among other
punishments. He is subject to a mandatory minimum sentence of ten years on each of
the two drug-conspiracy convictions on account of the weight involved. See 21 U.S.C.
§ 841(b)(1)(A)(viii). The government asserts that he is subject also to a mandatory
minimum sentence of five years for his conviction under § 924(c) that must run
consecutive to the ten-year sentences, resulting in a mandatory minimum prison sentence
of fifteen years (180 months). See 18 U.S.C. § 924(c)(1)(A)(i), (D)(ii). The government
concedes, however, that this mandatory minimum sentence was prohibited by our
precedent at the time Ambrose was sentenced, precedent the district court dutifully
followed when imposing the sentence. See United States v. Almany, 

,
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                       Page 30


241–42 (6th Cir.) (holding that a defendant convicted under § 924(c) who is already
subject to any mandatory minimum greater than the one required by § 924(c) is not
subject also to a mandatory, consecutive sentence for the § 924(c) conviction), judgment
vacated, 

(2010) (mem.). The sentence was lawfully imposed.

        However, while this appeal was pending, the Supreme Court decided Abbott v.
United States, 

(2010). The Court there held, directly contrary to Almany
(and the district court here), that a defendant convicted under § 924(c) is subject to the
highest mandatory minimum specified in that statute unless another statutory provision
directed to the very conduct § 924(c) proscribes—i.e., using, carrying, or possessing a
firearm in connection with a crime of violence or a drug-trafficking crime—requires a
higher mandatory minimum. 

29. Both parties agree that Abbott covers
Ambrose’s conviction under § 924(c). Because the district court declined to impose a
consecutive minimum sentence of five years for the conviction, Ambrose’s sentence is
now unlawful, and he must be resentenced. Cf. United States v. Taylor, 

,
411 (6th Cir. 2012).

        Ambrose makes two arguments in an attempt to avoid this result; both are
unconvincing. He first asserts that the government somehow forfeited its challenge to
Ambrose’s sentence by failing to argue, both here and below, that the sentence is
“unreasonable” or that the district court otherwise “abused its discretion.” Initially,
claims that a sentence is unreasonable or resulted from an abuse of discretion are
appellate arguments, so the government was not required to make them before the
district court. United States v. Vonner, 

, 389 (6th Cir. 2008) (en banc). In
any event, the government did argue at sentencing that Almany was wrongly decided.
And it has properly argued before us that the sentence is unlawful in light of Abbott.
That is sufficient.

        Ambrose next contends that subjecting him to a mandatory, consecutive sentence
of five years would violate concepts that underlie the Ex Post Facto Clause of the United
States Constitution. See U.S. Const. Art. I, § 9, cl. 3 (“No . . . ex post facto Law shall
be passed.”). Although that clause by its terms applies only to legislative enactments,
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                        Page 31


the Supreme Court has recognized that the Fifth Amendment’s Due Process Clause
provides similar protections with respect to retroactive application of judicial
interpretations of criminal statutes that are “unexpected and indefensible by reference
to the law which had been expressed prior to the conduct in issue.” Rogers v. Tennessee,

, 461 (2001) (quoting Bouie v. City of Columbia, 

, 354
(1964)). Due process entitles persons to “fair warning” that criminal liability will attach
to what previously had been lawful conduct. 

We have held that concepts
of “fair warning” protect individuals also from ex post applications of unforeseeable
judicial expansions of the punishments that result from a conviction, a protection
embodied in the Ex Post Facto Clauses themselves as interpreted by the Supreme Court,
see Weaver v. Graham, 

, 28 (1981). See Dale v. Haeberlin, 

,
934 (6th Cir. 1989).

       Here, Ambrose contends that the Supreme Court in Abbott interpreted § 924(c)
“directly contrary” to its plain language, thereby depriving him of fair warning of his
potential punishment. Even assuming the continued validity of our view that due
process protects against unforeseen judicial expansion of the punishments for known
criminal conduct (as opposed to the conduct proscribed), see Webb v. Mitchell, 

, 392 (6th Cir. 2009) (potentially calling Dale into doubt on this point in light of
Rogers v. Tennessee, 

(2001)), Ambrose’s position that he lacked fair
warning is difficult to reconcile with the unanimous views of the Justices in Abbott that
the statute unambiguously required a consecutive five-year sentence for those in
Ambrose’s position, 

n.9, and that the government’s contrary
position “gives effect to the statutory language,” 

Further, Ambrose is unable
to point to one decision in existence at the time he committed the offense that favored
his reading of the statute, thus making his claimed lack of fair warning less availing. Cf.

–57. (The first to go his way was United States v. Whitley, 

(2d Cir. 2008), decided one month after he committed the offense.)

       Finally, Ambrose asks us to apply the rule of lenity, which “requires ambiguous
criminal laws to be interpreted in favor of the defendants subjected to them.” United
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                    Page 32


States v. Santos, 

, 514 (2008). But given that the Supreme Court in Abbott
found § 924(c) unambiguous and declined to afford lenity in that case, we see no basis
for doing so here. 

n.9. For these reasons, Ambrose’s current
sentence is unlawful, and he must be resentenced consistent with Abbott (assuming, of
course, that his § 924(c) conviction survives the district court’s further factfinding
regarding the search).

                                         V.

       For these reasons, we DISMISS Miller’s appeal (Appeal No. 10–5432),
AFFIRM Beals’s convictions (Appeal No. 10–5264), VACATE Ambrose’s sentence,
and REMAND Ambrose’s case to the district court for proceedings consistent with this
opinion (Appeal Nos. 10–5877 and 10–6084).
Nos. 10-5264/5432/5877/6084 United States v. Beals, et al.                        Page 33


                               _______________________

                                   CONCURRENCE
                               _______________________

       TARNOW, Senior District Judge, concurring. While I agree with the Court’s
outcome, I write separately to note several troubling issues in Appellant Miller’s case.

       As noted by the Court, the law is clear that “defendants may waive their right to
appeal as part of a plea agreement so long as the waiver is made knowingly and
voluntarily.” United States v. Swanberg, 

, 625 (6th Cir. 2004). The
majority finds that Miller “does not contend that her plea was unknowing . . . .” Instead,
Miller argues that the waiver provision was not intended to cover a situation such as her
current appeal, or that the government breached the plea agreement.

       Because a plea agreement constitutes an agreement whereby a defendant gives
up their freedom to contest criminal charges, plea agreements create “special due process
concerns for fairness and the adequacy of procedural safeguards . . . .” United States v.
Ready, 

, 558 (2d Cir. 1996) (internal citations omitted). Plea agreements
“are to be interpreted strictly, with ambiguities construed against the government.”
United States v. Caruthers, 

, 470 (6th Cir. 2006) (citations omitted). In this
case, Miller’s plea agreement contained a waiver of appeal unless her eventual sentence
was “above the sentencing guideline range as determined by the district court.” The
Court finds, and I agree, that based on language of her waiver, Miller’s eventual
sentence was not above the guidelines range as determined by the district court - though
the district court’s determination of the guidelines range was contrary to the stipulated
facts in her plea agreement.

       The Court holds that Miller “could have bargained” for a narrower waiver, for
instance by including language that she reserved the right to appeal whether “the Court
incorrectly determined the guidelines range.” The Court thus implies that Miller
consciously chose to forego a more narrow waiver for some unstated advantage, or that
she was simply deficient in her bargaining and unnecessarily exposed herself to the
possibility of a higher sentence.
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        My point is not to question the Court’s holding that Miller’s waiver was knowing
and voluntary, but rather to note that requiring sophisticated bargaining by criminal
defendants to retain the right to appeal a sentence likely contributes to uncertainty
regarding whether a plea was knowing or voluntary. It does not seem to me that justice
is served by permitting plea agreements that (bargaining aside) result in defendants
agreeing to a plea that they did not intend or properly understand. Moreover, defendants
may have less incentive to accept guilty pleas if they are concerned that they are actually
at risk of a higher sentence than they thought had been agreed to in their plea agreement.

        I would recommend that counsel for both defendants and the government strive
to create plea agreements that state in plain terms the maximum possible sentence a
defendant might receive.1 Defendants who plead guilty based on an agreement that
provides a clear statement of the maximum likely sentence are adequately forewarned
of the possible consequences of their guilty plea, even in a “worst case” scenario where,
as here, a court construes the evidence and sentencing guidelines differently than a
defendant expected when agreeing to their plea.

        If discussion of the maximum possible sentence is required in plea agreements
the result is to eliminate ambiguity in the guilty-plea process, surely an important goal
given the interests at stake. In United States v. Shedrick, 

, 299-300 (3d Cir.
2007), the court found that a guilty plea was knowingly made in part because the
agreement explicitly stated that the defendant faced a maximum potential sentence of ten
years’ incarceration. The district court also discussed the maximum sentence during the
plea colloquy. The defendant could therefore not complain that he was unaware of the
consequences of his plea. In United States v. Williams, 

, 993 n.1 (7th Cir.
1999), the court found that, if an explicit stipulation was made as to the maximum
sentence, the district court should have rejected a plea agreement during the plea
colloquy where a mutual mistake of fact was present in the plea agreement as to the
maximum possible sentence. As a result of the mutual mistake, the United States Court


        1
           A judge is not bound by stipulations in plea agreements and may independently determine the
facts relevant to sentencing. U.S.S.G. § 6B1.4(d).
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of Appeals for the Third Circuit affirmed the district court’s decision to allow the
defendant to withdraw his plea of guilty.

        As another example of such a system in operation, 10 U.S.C. § 845(a), which
discusses plea agreements in the Uniform Code of Military Justice, states that “if it
appears that [the defendant] has entered the plea of guilty improvidently or through lack
of understanding of its meaning and effect, or if he fails or refuses to plead, a plea of not
guilty shall be entered in the record . . . .” Military courts have found that “a substantial
misapprehension of the maximum sentence may vitiate the providence of a plea of
guilty.” United States v. Walls, 

, 90-91 (C.M.A. 1980). Thus, most plea
agreements in military courts contain a provision concerning the maximum possible
sentence, without which a defendant cannot providently plead guilty.

        The plea agreement in this case does not mention the actual maximum possible
sentence that Miller might have (and did) receive. While a stipulation in a plea
agreement cannot bind a sentencing court to a particular sentence, plea agreements
should state the maximum possible sentence that a defendant might receive and, if
subjected to a sentence above that maximum, waivers of appeal should not be enforced.