                                       PRECEDENTIAL

       UNITED STATES COURT OF APPEALS
            FOR THE THIRD CIRCUIT

                      __________

                      No. 14-4628
                      __________

           UNITED STATES OF AMERICA,

                           v.

             THOMAS DAVID STEINER,
                                           Appellant
                      __________

     On Appeal from the United States District Court
        for the Western District of Pennsylvania
          (D.C. Crim. No. 2-11-cr-00089-001)
      District Judge: Honorable Joy Flowers Conti
                       __________

 On Remand from the Supreme Court of the United States
                 November 28, 2016

Submitted on Appellant’s Motion to Summarily Remand and
            Parties’ Supplemental Submissions
                    December 30, 2016

         (Originally Argued: November 6, 2015)
    Before: FUENTES,* JORDAN, and VANASKIE, Circuit
                         Judges

        (Opinion on Remand Filed: February 1, 2017)
                       __________

W. Penn Hackney
Renee Pietropaolo [Argued November 6, 2015]
Office of Federal Public Defender
1001 Liberty Avenue
1500 Liberty Center
Pittsburgh, PA 15222

       Counsel for Appellant Thomas David Steiner

Rebecca R. Haywood
Jane M. Dattilo      [Argued November 6, 2015]
Office of United States Attorney
700 Grant Street
Suite 4000
Pittsburgh, PA 15219

       Counsel for Appellee United States of America



                OPINION OF THE COURT




*
 Honorable Julio M. Fuentes assumed senior status on July
18, 2016.




                             2
FUENTES, Circuit Judge.

       This case returns to us on a “grant, vacate, and
remand” (“GVR”) order of the Supreme Court of the United
States. Our earlier precedential opinion and judgment of
March 3, 2016 had affirmed defendant-appellant Steiner’s
conviction for possession of ammunition by a convicted felon
(18 U.S.C. § 922(g)(1)).1 We did not reach challenges to
Steiner’s sentence, as he had not raised any.

       The Supreme Court’s GVR order 2 instructs us to
reconsider our decision in light of Mathis v. United States,3
the Court’s latest case about predicate offenses and the
“categorical approach.” We asked the parties to file short
supplemental statements addressing both the impact of Mathis
on our previous opinion and the merits of Steiner’s Mathis
challenge more generally; Steiner also separately moved to
remand for expedited resentencing. Both Steiner and the
government agree that Mathis did not affect the validity of
our earlier decision affirming Steiner’s conviction. They also
agree that it does affect Steiner’s sentence; the District Court
used a 1993 Pennsylvania burglary conviction as a predicate
“crime of violence” under the United States Sentencing
Guidelines, which the government now concedes was plain
error.




1
 See generally United States v. Steiner, 815 F.3d 128 (3d Cir.
2016).
2
    See Steiner v. United States, 137 S. Ct. 494 (2016).
3
    136 S. Ct. 2243 (2016).




                                 3
        Because we agree with the parties that, under Mathis,
Steiner’s 1993 burglary conviction was not a predicate “crime
of violence” under the Guidelines—and, thus, that his
Guidelines range should not have been enhanced—we will
grant Steiner’s motion for summary action, vacate the District
Court’s judgment of sentence, and remand for expedited
resentencing. Steiner is to be released from federal custody
pending resentencing, subject to the supervised release terms
contained in the District Court’s judgment of sentence. And
because our previous precedential opinion was not at all
affected by Mathis, we will once again affirm Steiner’s
conviction. We therefore revise and reissue below our
previous precedential opinion as altered by our Mathis
discussion and the alternative disposition it requires.

                   I.     BACKGROUND4

A.    INTRODUCTION

       During the execution of two separate search warrants
at properties that police believed were owned or occupied by
defendant Thomas Steiner, police seized, among other things,
a sawed-off shotgun, .32 and .38 caliber ammunition, and 12
gauge shotgun ammunition. As a result, Steiner was indicted
on two counts for being a felon-in-possession of a firearm and
ammunition in violation of 18 U.S.C. § 922(g). Following a
4-day trial, he was convicted on one count of felony-


4
  Subject matter jurisdiction was conferred upon the District
Court by 18 U.S.C. § 3231.           We exercise appellate
jurisdiction under 28 U.S.C. § 1291 and 18 U.S.C. § 3742(a).




                              4
possession of ammunition and sentenced to an 87-month
prison term.

        During the trial, the government introduced into
evidence the fact that a warrant had issued for Steiner’s arrest
on an unrelated charge. Steiner contends that the District
Court improperly admitted evidence of the arrest warrant that
was unrelated to the offenses he faced at trial. He also argues
that the District Court erred by failing to instruct the jury that
it was required to reach a unanimous verdict as to each type
of ammunition seized. While we conclude that the admission
of the unrelated arrest warrant was error, the error was
harmless. We also conclude that the District Court did not err
when it declined to provide a unanimity instruction. For the
reasons that follow, we will affirm the conviction. As
intervening Supreme Court precedent has affected the validity
of Steiner’s 87-month sentence—an error that the government
concedes is worthy of remand—we will vacate the judgment
of sentence and remand for expedited resentencing.

B.     STING OPERATION, SEARCH, AND INDICTMENT

       This case arises from a sting operation. In August
2007, police informant Timothy Stants told Pennsylvania
State Trooper Thomas Baumgard that Thomas Steiner, a
convicted felon, was staying on his (Stants’) property and was
“on the run” from law enforcement. Stants also claimed that
Steiner had a sawed-off shotgun, which Steiner had described
to him as a “cop killer,” and that Steiner said he would use
the gun to avoid being arrested. Stants claimed that the
shotgun would be found in a camper on Stants’ property.

      Based on Stants’ tip, Baumgard obtained a search
warrant for the camper. Before executing the warrant on




                                5
August 27, 2007, Baumgard paid Stants $100 for his help in
securing Steiner’s arrest and told Stants to drive Steiner to a
nearby gas station. There, officers would be waiting to arrest
Steiner on a warrant that had issued for Steiner’s arrest for
failure to appear at a preliminary hearing scheduled that same
day, on an unrelated sexual assault charge. Baumgard
conducted his search of the camper in the afternoon, just after
Stants drove Steiner away to the gas station. He found,
among other things, a sawed-off shotgun loaded with six
rounds of 12-gauge shotgun ammunition; a wallet containing
various documents, all bearing Steiner’s name; and a
discharged shotgun shell. Soon after the search, Baumgard
ordered Steiner arrested on the warrant issued for his failure
to appear at the preliminary hearing earlier that day. At the
time of his arrest, Steiner was in Stants’ car at a nearby gas
station.

       Apparently, there was more to the story than the gun
and ammunition found in the camper. Stants also told police
that he had seen the missing pieces of the sawed-off shotgun
(part of the barrel and stock) at a home that Steiner
supposedly owned, located at Meadow Avenue (the “home”
or the “Meadow Avenue home”). Based on Stants’ tip, police
obtained another search warrant, this time for the home.

      Police executed the search warrant for the home on
August 29, 2007. When they arrived, they entered the
basement of the home, which was in disarray.5 There, they
found a shotgun stock on the bar and a shotgun barrel in the


5
  The basement was also referred to in the indictment and at
other points during trial as the “downstairs area.”




                              6
ceiling where a tile was missing. 6 Also, they discovered a
hacksaw and pipe wrenches on the basement floor and a
single 12-gauge shotgun shell in a pocket of the pool table.
Four other 12-gauge shotgun shells were found in a bowl, on
top of which was Steiner’s notice of impending warrant of
arrest. In addition to the shotgun ammunition, the police also
discovered a variety of other types of ammunition, including
20 rounds of .32 caliber ammunition and 17 rounds of .38
Special ammunition.

       Based on the shotgun and ammunition found in the
camper, a grand jury charged Steiner with one count of being
a felon-in-possession of a firearm and ammunition in
violation of 18 U.S.C. § 922(g). A superseding indictment
was filed several months later, adding a second count
charging Steiner with a violation of § 922(g) based on the
ammunition found in the home.

C.     THE TRIAL

           1. Testimony

        The government’s case against Steiner proceeded to a
jury trial. 7 At trial, Steiner stipulated to having a prior felony


6
  A forensic expert later matched the stock and barrel found in
the basement to the sawed-off shotgun found in the camper.
7
  The government proceeded against Steiner on a theory of
constructive possession of the firearm in the camper and the
ammunition found in his home. Constructive possession
occurs when a person not in actual possession “knowingly has
both the power and the intention at a given time to exercise
dominion or control over a thing, either directly or through




                                7
conviction. He testified in his own defense and denied that he
ever owned or possessed the shotgun or ammunition seized
from either the camper or the basement of the home. Steiner
also acknowledged that he owned the wallet found in the
camper and admitted that he owned the Meadow Avenue
home at some point in 2007.

        Steiner’s ex-wife, Greta Steiner, was called as a
witness. She testified that although she had been living at a
different address in 2007, she occasionally stopped at the
Meadow Avenue home to retrieve her belongings. She also
testified that during these visits she saw neither firearms nor
ammunition in the home but she recalled having stored boxes
of antique ammunition that belonged to her deceased ex-
husband in the home’s garage. She denied that anyone ever
brought the ammunition into the home and claimed that
Steiner was unaware of the ammunition. Neither Steiner nor
the government presented evidence about whether the
ammunition stored in the garage may have been moved to the
basement.

       Mark Williams, Stants’ close friend, testified for the
government. Williams claimed that he had been inside
Steiner’s home in August 2007 because he was interested in
purchasing the property. 8 At that time, Williams said that he
noticed the shotgun barrel and the hacksaw laying on a
homemade bar and pointed them out to Stants. Williams also

another person or persons.” United States v. Garth, 188 F.3d
99, 112 (3d Cir. 1999) (emphasis omitted).
8
  Stants and Williams further testified that Steiner sold the
house before police searched it, and Williams claimed that his
wife had notarized the paperwork for that sale.




                              8
claimed that Steiner told him that he “wouldn’t go easy” if the
police tried to arrest him.

       Stants also testified. He denied receiving any benefit
for his help in securing Steiner’s arrest, despite Baumgard’s
testimony that he had paid Stants $100 for his assistance. He
also corroborated Williams’ testimony regarding the
basement of the home and admitted that he had visited
Steiner’s home twice in Steiner’s absence.

             2. The Government’s Arrest Warrant Evidence

        During Steiner’s trial, the government introduced the
arrest warrant that had issued based upon Steiner’s failure to
appear on the sexual assault charge. The government argued
that the arrest warrant,9 though not the underlying conduct,
was admissible to show that Steiner “was on the run from law
enforcement at the time, hiding out in this trailer,” and was
intending to “evade the warrant and not appear” at the
preliminary hearing because “[t]hat’s what led officers to his
trailer in the first place.” 10 The government claimed that the
arrest warrant “complete[d] the story” because it was
“background of what led law enforcement to Mr. Steiner to
begin with in this case.” 11 However, this was not true.
Stants’ tip regarding the shotgun was the actual source of the

9
  Our references to the unrelated arrest warrant are also, by
extension, to any testimony or other evidence related to that
warrant.
10
     (App. at 116.)
11
     (App. at 116.)




                              9
government’s initial interest in Steiner. The District Court,
relying on the government’s representation, admitted the
arrest warrant evidence as “background” under Federal Rule
of Evidence 404(b). The court reasoned that, as long as the
underlying conduct was not admitted, any prejudice to Steiner
was minimized. The court, though, expressly rejected any
argument that the evidence could be admitted to prove
Steiner’s motive or intent under Rule 404(b).

         3. The District Court’s Jury Instruction on
         Unanimity

       The government requested that the jury be instructed
that although the defendant was charged with possessing
ammunition in different varieties or from different locations,
it need not unanimously agree on which ammunition he
possessed to convict him of felony possession under § 922(g).
Steiner objected and requested that the jury be instructed that
it must agree as to which ammunition Steiner possessed,
adding that the indictment was confusing. The District Court
adopted the government’s position and instructed the jury that
unanimity was not required with respect to the firearm or
ammunition. Specifically, the court stated:

       Although all jurors must agree with respect to
       Count 1 that the Defendant possessed a firearm
       or ammunition and with respect to Count 2 that
       the Defendant possessed different ammunition,
       you need not all agree on the exact item
       possessed. For example, if a Defendant was
       charged with possessing one piece of
       ammunition found in the bedroom, one piece of
       ammunition found in the living room, and one
       piece of ammunition found in the basement, you




                              10
         must all unanimously agree that the Defendant
         possessed at least one piece of ammunition in
         order to convict. You do not have to agree on
         which one or if he possessed more than one.

         Therefore, it would be sufficient if ten jurors
         determined that he possessed one piece of
         ammunition in the bedroom, one juror
         determined that he possessed one piece of
         ammunition found in the basement, and one
         juror determined that he possessed them all. In
         other words, if the Defendant is alleged to have
         been in possession of ammunition of different
         varieties or from different locations, you must
         all find that as to the ammunition charged in
         each count he possessed at least some
         ammunition as charged in that count in order to
         convict, but . . . need not all agree with respect
         to a count on exactly which ammunition was
         actually possessed as charged in that count. 12

       The jury found Steiner not guilty on Count One
(charging possession of the gun and ammunition in the
camper), but guilty on Count Two (charging possession of the
ammunition found in the Meadow Avenue home).

        II.    CHALLENGES TO STEINER’S CONVICTION

      A. Admission of the Arrest Warrant

       First, Steiner argues that the District Court erred by
admitting evidence of the arrest warrant that had issued for

12
     (App. at 342, 487-88.)




                                11
his failure to appear at a preliminary hearing on an unrelated
charge. The District Court stated during the in limine hearing
on the admissibility of the arrest warrant, and memorialized
in its minute entry, that its decision rested on Rule 404(b)
grounds.13 Based on the government’s representations, the
court admitted the evidence as “background” or to “complete
the story” of the felon-in-possession crime.

       Steiner argues that, while courts in this Circuit have
occasionally admitted prior-act evidence under Rule 404(b)
for the purpose of “completing the story” or providing
“background,” they have also generally limited the use of
those purposes to conspiracy cases.        In response, the
government asserts that the arrest warrant was properly
admitted under Rule 404(b) because it identified a proper
purpose for the evidence: it was necessary to provide
background and complete the story of Steiner’s arrest,
interrogation, and the police investigation of the crimes
charged.


13
   In its minute entry, the court stated: “[w]ith respect to the
government’s motion in limine on 404(b) evidence [ECF No.
99], the government may, as background, refer to the fact that
defendant was arrested on an outstanding warrant, but may
not address the specifics of the warrant or underlying charge.”
(App. at 28.) The District Court also stated numerous times
on the record that the information was admitted only for
background purposes. (App. at 117, 119.) Therefore,
Steiner’s argument that the District Court may have
improperly admitted the arrest warrant evidence as “intrinsic”
evidence that directly proved the crime, as opposed to prior-
act evidence under Rule 404(b), is meritless.




                              12
       For the reasons that follow, we conclude that the
District Court erred by admitting the arrest warrant.

             1. Admission of the Arrest Warrant Under
                Rule 404(b)

       We review the District Court’s evidentiary rulings
principally on an abuse of discretion standard, which occurs
only when the district court’s decision is “arbitrary, fanciful,
or clearly unreasonable”—in short, where “no reasonable
person would adopt the district court’s view.” 14 We conduct
“plenary review, however, of [the District Court’s] rulings to
the extent they are based on a legal interpretation of the
Federal Rules of Evidence.” 15 This includes plenary review
“of whether evidence falls within the scope of Rule 404(b).” 16

       Rule 404(b) provides that evidence of other crimes,
wrongs, or acts is not admissible to prove character or
demonstrate action in conformity with those acts. 17 Prior-act
evidence, though, may be admitted “for another purpose, such
as proving motive, opportunity, intent, preparation, plan,
knowledge, identity, absence of mistake, or lack of
accident.” 18 To be admissible, prior-act evidence must satisfy
the test set forth in Huddleston v. United States.19 As the
14
     United States v. Starnes, 583 F.3d 196, 214 (3d Cir. 2009).
15
  Complaint of Consolidation Coal Co., 123 F.3d 126, 131
(3d Cir. 1997).
16
     United States v. Cruz, 326 F.3d 392, 394 (3d Cir. 2003).
17
     Fed. R. Evid. 404(b)(1).
18
     Fed. R. Evid. 404(b)(2).
19
     485 U.S. 681 (1988).




                                13
Supreme Court stated there, the proffered evidence must be:
(1) offered for a proper purpose under Rule 404(b)(2); (2)
relevant to that purpose; (3) sufficiently probative under the
Rule 403 balancing requirement; and (4) accompanied by a
limiting instruction, if requested. 20 And, “[u]nless the reason
is apparent from the record, a mere list of the purposes found
in Rule 404(b) is insufficient.”21 Indeed, “[t]he district court
must put a chain of inferences into the record, none of which
is the inference that the defendant has a propensity to commit
this crime.” 22

       In United States v. Green, we concluded that “allowing
the jury to understand the circumstances surrounding the
charged crime—completing the story—is a proper, non-
propensity purpose under Rule 404(b).” 23 We also stated that
prior-act evidence is admissible to supply “helpful
background information to the finder of fact.” 24 With all of
this in mind, one might ask: is not all evidence helpful to
providing background to the factfinder? The answer is yes.
But not all helpful evidence is relevant to a proper purpose
under Rule 404(b).

      In fact, Steiner is correct that the majority of criminal
cases in which we have deemed “background” a proper


20
     Id. at 691-92.
21
  United States v. Sampson, 980 F.2d 883, 888 (3d Cir.
1992).
22
     Id.
23
     617 F.3d 233, 247 (3d Cir. 2010).
24
     Id. at 250.




                                14
purpose involve conspiracies.25 And there is no conspiracy
involved in this case. Also, in at least one opinion that
preceded our decision in Green, we specifically warned that,
while courts have occasionally admitted prior crimes
evidence as “background,” “this label is uninformative at best
and, at worst, can be an unacceptable substitute for the
analysis required by Rule 404(b).” 26

       There are unique characteristics that render
“background” a proper purpose for admitting prior-act
evidence in conspiracy cases. For instance, in proving the
existence of a conspiracy, a court might allow a party to
present background evidence revealing an ongoing


25
   See, e.g., United States v. O’Leary, 739 F.2d 135, 136-37
(3d Cir. 1984) (identifying the need to show “the background
of the charges [and] the parties’ familiarity with one another”
as a proper purpose); United States v. Simmons, 679 F.2d
1042, 1050 (3d Cir. 1982) (admitting similar criminal activity
perpetrated before the period charged in the indictment to
furnish essential background information, to demonstrate a
continuing relationship between an unindicted co-conspirator
and the defendant, and to assist the jurors in understanding
the unindicted co-conspirator’s role in the forgery scheme);
United States v. Dansker, 537 F.2d 40, 58 (3d Cir. 1976) (in
conspiracy case, upholding introduction of prior criminal acts
by defendants because “the background information provided
by this testimony enabled the jury to better understand [the
witness’s] role in the bribery scheme as well as his testimony
as a whole”).
26
  United States v. Echeverri, 854 F.2d 638, 644 (3d Cir.
1988).




                              15
relationship between co-conspirators.27 Likewise, this Court
affirmed the admission of background evidence to help the
jury understand one conspirator’s role in a complex scheme. 28
But neither of those models applies in this case.

        Here, Steiner is the only defendant. There was no
need for the government to explain a complicated backstory.
We are not suggesting that conspiracy cases are the only ones
in which background facts may be admissible as 404(b)
evidence. We are saying that, when the information needed
to understand what happened in a case is straightforward and
easily understood without reference to facts that do not bear
on the charged offense, forcing extraneous and potentially
prejudicial information into the record in the name of
“background” is not defensible under Rule 404(b). That,
unfortunately, is what happened here. Stants’ tip entirely
explained why the government was focusing on Steiner. In
fact, the arrest warrant evidence was completely irrelevant to



27
   See, e.g., United States v. Corbin, No. 10-352, 2011 WL
2110831, at *2 (E.D. Pa. May 26, 2011) (finding that the
defendants’ prior gunpoint robberies of drug dealers were
admissible to establish the relationships between the
defendants and to explain the background of the conspiracy),
aff’d, 607 F. App’x 136, 139-40 (3d Cir. 2015)
(nonprecedential).
28
  See United States v. Butch, 256 F.3d 171, 176 (3d Cir.
2001) (finding no abuse of discretion and affirming
conviction where the District Court admitted the
government’s background evidence “to help the jury
understand the co-conspirator’s role in the scheme”).




                             16
the government’s case. 29 We therefore find this case to be
sufficiently distinct from cases in which “background”
evidence may be admissible under Rule 404(b).

       In Green, by contrast, we concluded that the
background information—evidence that the defendant
threatened to kill a police officer—was properly admitted
under Rule 404(b) because it fit “into a chain of logical
inferences” and explained why the defendant was under
investigation for the crime charged, attempted possession
with intent to distribute cocaine.30 We also held that the
information was properly admitted for the purpose of proving
the informant’s motive to cooperate, which was put at issue
by the defendant. 31 We therefore find Green distinguishable
insofar as the prior-act evidence there served to complete the
story of the crime charged. Here, we conclude that evidence
of the outstanding arrest warrant on the unrelated sexual
assault charge had nothing whatsoever to do with Steiner’s
charged crime of felony possession of a weapon or
ammunition under § 922(g).

       Again, to be clear, we do not conclude that any
evidence offered for the purpose of providing background is
only admissible in conspiracy cases. There may—and likely

29
  As to the second Huddleston factor, relevance, Fed. R.
Evid. 401 provides that “[e]vidence is relevant if (1) it has
any tendency to make a fact more or less probable than it
would be without the evidence, and (2) the fact is of
consequence in determining the action.”
30
     Green, 617 F.3d at 250.
31
     Id.




                               17
will—be other situations in which such evidence is
admissible outside of the conspiracy context. Nor do we
venture to paint the absolute contours of when prior-act
evidence may be admissible to provide background under
Rule 404(b). We simply conclude that, on these facts, the
District Court abused its discretion by admitting the arrest
warrant evidence for the purpose of providing background.

       To be sure, the District Court was not entirely, or even
primarily, to blame for its error. The government played a
central role. Here, the prosecutor wrongly asserted that the
government needed the unrelated arrest warrant to prove that
Steiner was guilty of felony possession. Yet it is clear to us
that the government did not need the arrest warrant to try a
case against Steiner at all. The government had Stants’ tip,
Stants’ and Williams’ testimony that Steiner owned the home
in 2007 and possessed a shotgun, and a stipulation that
Steiner was a felon. Taken together, this evidence strongly
supported the government’s theory that Steiner unlawfully
possessed the firearm and ammunition. The only purpose the
arrest warrant served was to improperly suggest that Steiner
was predisposed to commit criminal acts.

       In sum, we are deeply troubled by the government’s
inaccurate claim that the arrest warrant was “what led officers
to [Steiner’s] trailer in the first place,” and we are persuaded
that that inaccuracy led the District Court to err by admitting
evidence of the warrant.32 We therefore admonish the




32
     (App. at 116.)




                              18
government to take greater care in its representations to the
trial court and not brandish Rule 404(b) so cavalierly.33

          2. Whether the error was harmless

       While we find that the District Court improperly
admitted the arrest warrant, we conclude that the error was
harmless.34 We can call a nonconstitutional error harmless,
and uphold the conviction, if there is a high probability that
“the error did not contribute to the judgment,” requiring us to
have a “sure conviction that the error did not prejudice the
defendant.”35

       First, the arrest warrant evidence had no prejudicial
impact on the jury’s determination as to Count One, because
Steiner was found not guilty of that charge. It is therefore
reasonable to infer that the evidence had no effect as to Count

33
   Because we conclude that the District Court erred by
admitting the arrest warrant evidence as “background,” we
need not reach Steiner’s argument that the court failed to
conduct a proper Rule 403 analysis. Nor need we reach the
government’s argument that Steiner waived his Rule 403
argument by failing to object. And, as to the fourth
Huddleston factor, we note that the District Court did not give
a limiting instruction to the jury because Steiner did not
request one.
34
    Fed. R. Crim. P. 52(a) provides: “Any error, defect,
irregularity, or variance that does not affect substantial rights
must be disregarded.”
35
   United States v. Caldwell, 760 F.3d 267, 285 (3d Cir. 2014)
(citations omitted); see also United States v. Cross, 308 F.3d
308, 326 (3d Cir. 2002).




                               19
Two. Second, the District Court did not disclose the conduct
underlying the arrest warrant, that is, the alleged sexual
assault of a minor. Third, at trial, Steiner stipulated to having
a prior felony conviction. Also, when he took the stand,
Steiner admitted that he was previously convicted of crimes
of falsehood: burglary, theft, and felony forgery. And finally,
the ample evidence presented surrounding Steiner’s
ownership and occupation of the home, Stants’ and Williams’
testimony regarding the same, and the lack of evidence
linking the antique ammunition in the garage to the
ammunition found in the home, convinces us that the
additional arrest warrant evidence did not affect the jury’s
guilty verdict as to Count Two.

       We therefore conclude that any error in admitting the
prior act evidence under Rule 404(b) was harmless.

     B. Steiner’s Jury Instruction Challenge

       Next, Steiner argues in his briefs that the District Court
erred by refusing to instruct jurors that they must
unanimously agree as to which ammunition he possessed to
find him guilty under Count Two. In support of his claim,
Steiner argues that the government improperly bundled into
Count Two multiple, distinct violations of § 922(g), each of
which should have been prosecuted as a separate violation of
the statute. 36 Put another way, he claims that the indictment

36
  The government argues that Steiner waived any “duplicity”
argument by not raising it below. We disagree. Steiner never
moved to dismiss the indictment before or during trial on the
grounds that the government improperly joined possession of
separate types of ammunition into one count. However,
Steiner’s counsel clearly objected to the jury instruction,




                               20
was “duplicitous” because the government improperly joined
possession of separate types of ammunition into one count. 37
To cure this defect, Steiner contends that the District Court
should have instructed the jury that it had to unanimously
determine which ammunition Steiner possessed to find him
guilty on Count Two. By expressly declining to give this
curative jury instruction, Steiner argues that the District Court
deprived him of his Sixth Amendment right to a unanimous
jury verdict, and therefore his conviction under Count Two
should be vacated.

       We reject Steiner’s argument. In our view, the
evidence at trial overwhelmingly demonstrated that Steiner
possessed the ammunition in one part of the Meadow Avenue
home, which he owned in 2007. For the additional reasons
that follow, we therefore conclude the indictment properly
charged Steiner with a single violation of § 922(g) under
Count Two and that a special unanimity instruction was not
required.




specifically requesting that the jury be instructed that it must
agree as to which ammunition Steiner possessed and adding
that the “indictment [c]ounts [were] confusing.” (App. at 97.)
In consequence, we find that Steiner’s “duplicity” argument
was preserved on appeal in connection with his jury
instruction challenge.
37
  Count Two of the indictment charged possession of various
pieces of ammunition in the “downstairs area” of the home.




                               21
       Whether an indictment is duplicitous is a question of
law subject to de novo review.38 We also review de novo
“whether the jury instructions stated the proper legal
standard.” 39 “We review the refusal to give a particular
instruction or the wording of instructions for abuse of
discretion.”40

       Duplicity is the improper combining of separate
offenses into a single count. 41 When a defendant’s Sixth
Amendment right to a unanimous jury verdict is jeopardized
by a duplicitous indictment, a court can cure the indictment
by issuing a limiting instruction requiring the jury to
unanimously find the defendant guilty of at least one distinct
act.42

        Under Federal Rule of Criminal Procedure
12(b)(3)(B), a motion alleging a defect in the indictment must
be made before trial. Yet while a defendant waives technical
errors to an indictment by his failure to object to the duplicity
before trial, courts have held that the alleged harm to the
defendant’s substantive rights resulting from a duplicitous
indictment can be raised at trial or on appeal, notwithstanding

38
     United States v. Haddy, 134 F.3d 542, 547 (3d Cir. 1998).
39
     United States v. Coyle, 63 F.3d 1239, 1245 (3d Cir. 1995).
40
     United States v. Leahy, 445 F.3d 634, 642 (3d Cir. 2006).
41
     Haddy, 134 F.3d at 548.
42
   See, e.g., United States v. Newell, 658 F.3d 1, 20-28 (1st
Cir. 2011); United States v. Yielding, 657 F.3d 688, 702 (8th
Cir. 2011); United States v. Pietrantonio, 637 F.3d 865, 869
(8th Cir. 2011); United States v. Starks, 472 F.3d 466, 471
(7th Cir. 2006).




                                22
the defendant’s failure to make a pretrial motion. 43 “The
rationale for this distinction is that, whereas Rule 12 applies
only to defects in the institution of criminal proceedings . . . ,
a verdict rendered by a less-than-unanimous jury violates a
defendant’s Sixth Amendment rights by a harm that arises
from the trial itself.”44

        Count Two of the indictment charged Steiner with a
violation of 18 U.S.C. § 922(g), which, in relevant part,
provides: “It shall be unlawful for any person who has been
convicted in any court of a crime punishable by imprisonment
for a term exceeding one year . . . to ship or transport in
interstate or foreign commerce, or possess in or affecting
commerce, any firearm or ammunition; or to receive any
firearm or ammunition which has been shipped or transported
in interstate or foreign commerce.”

        To determine whether Count Two was duplicitous, we
first focus on the “allowable unit of prosecution” to decide
whether the indictment properly charges a violation of the
relevant statute. 45 We have held that the allowable unit of

43
   United States v. Adesida, 129 F.3d 846, 849 (6th Cir.
1997); see also United States v. Robinson, 627 F.3d 941, 958
(4th Cir. 2010) (noting that “[i]t is black letter law that
duplicitous indictments can be cured through appropriate jury
instructions”); Haddy, 134 F.3d at 547-48.
44
   United States v. Kakos, 483 F.3d 441, 444 (6th Cir. 2007)
(citing Davis v. United States, 411 U.S. 233, 241 (1973), and
Johnson v. Louisiana, 406 U.S. 356, 369 (1972) (Powell, J.,
concurring)).
45
     Haddy, 134 F.3d at 548.




                               23
prosecution under § 922(g) is the “incident of possession,”
regardless of whether a defendant possessed more than one
firearm, or possessed a firearm and ammunition. 46 In other
words, we ask if the evidence establishes that the defendant
committed a single act of possessing firearms or ammunition,
or instead whether the evidence indicates that multiple,
distinct acts of unlawful possession occurred.

       We have also stated that simultaneous possession of
multiple firearms or pieces of ammunition does not give rise
to a separate offense for each firearm or piece of ammunition
possessed.47 Likewise, multiple convictions for possession of
multiple firearms may be appropriate where the firearms in
question were seized in different locations or if they were
acquired in separate transactions. 48

       These observations lead us to the question of how we
determine whether an indictment is duplicitous when
someone is charged with felony possession of various types
of ammunition, all of which are located in the basement of a
home. In resolving Steiner’s challenge, our prior cases
provide us with sufficient guidance. In this case, we conclude
that the indictment was not duplicitous and that a curative
jury instruction was not required.

46
     United States v. Tann, 577 F.3d 533, 537 (3d Cir. 2009).
47
     Id.
48
   See, e.g., United States v. Verrecchia, 196 F.3d 294, 298
(1st Cir. 1999) (concluding that the government properly
charged the defendant with two counts of possessing a
firearm in violation § 922(g) where twenty-three guns were
recovered from the same defendant in two separate locations).




                                24
       In United States v. Marino and United States v.
Frankenberry, we held that the simultaneous possession or
receipt of several firearms by a convicted felon constituted a
single offense under the predecessor statutes to § 922(g),
absent a showing that the weapons were separately stored or
acquired.49    We further elaborated on the concept of
simultaneous possession in United States v. Tann. In Tann,
the indictment charged the defendant with two separate
§ 922(g) violations based upon possession of a gun found in
the bathroom where he was arrested and ammunition that was
located in his pocket at the same time. 50 There, we
determined that the two items were simultaneously possessed.
As a result, we concluded that possession of both a firearm
and ammunition, seized at the same time in the same location,
supported only one conviction and sentence under § 922(g). 51

       However, in United States v. Kennedy, we held that
mere physical proximity does not demonstrate simultaneous
possession. 52 There, we declined to find simultaneous
possession where firearms were stored in two separate
vehicles located on the same premises.53 In reaching this
conclusion, we specifically noted that, when determining

49
 United States v. Frankenberry, 696 F.2d 239, 245-46 (3d
Cir. 1982) (analyzing 18 U.S.C. § 922(h)); United States v.
Marino, 682 F.2d 449, 454 (3d Cir. 1982) (analyzing 18
U.S.C. § 1202(a)).
50
     Tann, 577 F.3d at 536-37.
51
     Id. at 537.
52
     682 F.3d 244, 256 (3d Cir. 2012).
53
     Id.




                                 25
whether firearms are simultaneously possessed, what matters
is the defendant’s “course of . . . treatment of the firearms,”
which “may not be viewed in a frozen, momentary state
immediately prior to the seizure.” 54 We therefore held that
the district court erred when it merged two separate felony
possession counts for purposes of resentencing the
defendant.55

       These cases demonstrate that determining whether
individual firearms or ammunition were simultaneously
possessed is a highly fact-driven inquiry that depends on the
circumstances surrounding a defendant’s alleged conduct.

       Here, other than Steiner’s testimony, there is little, if
any, evidence supporting Steiner’s contention that the
ammunition found in the home was acquired at different
times and for different purposes, or that it was separately
stored in the home. By contrast, the evidence at trial strongly
demonstrated that Steiner owned the home in 2007 and that
all of the ammunition was stored in various parts of the
basement.56 Moreover, at least some of the 12-gauge
ammunition was literally found resting under Steiner’s notice
of impending warrant of arrest. And, while Steiner’s ex-wife


54
  Id. at 255-56 (quoting United States v. Mullins, 698 F.2d
686, 687 (4th Cir. 1983)).
55
     Id.
56
   While Stants and Mark Williams testified that Steiner sold
the house before the August 29 search and that Williams’
wife notarized the paperwork, other testimony also confirms
that Steiner owned the house sometime in 2007 before
abandoning it.




                              26
testified that she brought various types of antique ammunition
into the garage in 1999, none of the ammunition that Steiner
was charged with possessing was located in the garage, and
none of the physical evidence specifically linked the
ammunition found in the basement to Greta Steiner or her
deceased ex-husband. Moreover, even if we accepted that
Greta Steiner purchased the ammunition found in the
basement in the first instance, the jury could have found that
Steiner himself later acquired the ammunition from Greta
Steiner, and not, as Steiner claims, from other sources on
other occasions.

       In sum, we conclude that the indictment was not
duplicitous. Accordingly, the District Court’s failure to give
a special unanimity instruction as to Count Two did not
constitute a violation of Steiner’s Sixth Amendment right to a
unanimous jury verdict.57



57
     Kakos, 483 F.3d at 446.
Steiner also asks us to reconsider our current legal standard
for assessing claims of pre-indictment delay. See United
States v. Beckett, 208 F.3d 140, 150-51 (3d Cir. 2000)
(defendant must show both actual prejudice and deliberate
delay) (citing United States v. Ismaili, 828 F.2d 153, 168 (3d
Cir. 1987)). However, “[u]nder a longstanding practice of
our Court, a panel may not overrule another panel decision.”
Pa. Pharmacists Ass’n v. Houstoun, 283 F.3d 531, 534 (3d
Cir. 2002); see also 3d Cir. I.O.P. 9.1. We therefore will not
undertake to reconsider our standard for reviewing claims of
pre-indictment delay. Moreover, we conclude that contrary to
Steiner’s assertion, the District Court applied the correct legal




                               27
     III.   CHALLENGE TO STEINER’S SENTENCE AFTER
                        MATHIS

         We now turn to Steiner’s challenge to his sentence,
which he invoked in his petition for certiorari (but not in his
initial appeal to us).58

       By way of background, the offense Guideline
applicable to Steiner’s § 922(g) conviction is § 2K2.1, 59
which sets out various base offense levels that depend on the
circumstances of the offense and the defendant’s criminal
history. At sentencing, the District Court determined that the
appropriate base offense level was 20—corresponding to
§ 2K2.1(a)(4)(A)—because of a predicate conviction for a
“crime of violence”: a 1993 Pennsylvania burglary
conviction. Section 2K2.1 does not itself define “crime of
violence.” Instead, it refers to the language of § 4B1.2(a),
which specifically defines “burglary of a dwelling” as a crime
of violence. Alongside Steiner’s criminal history score of VI,
a base offense level of 20 yielded a Guidelines range of 70–
87 months in prison. As mentioned earlier, Steiner was
sentenced to the high end of that range, receiving 87 months.


standard when it denied Steiner’s motion to dismiss the
indictment for pre-indictment delay.
58
   Steiner’s sentence was the subject of extensive litigation
before the District Court, but we need not recount that history
now. See generally Tentative Findings and Rulings, ECF No.
152 (discussing the parties’ sentencing positions and the
District Court’s preliminary findings).
59
  We refer throughout to the 2013 edition of the Guidelines
manual.




                              28
       Steiner filed a petition for certiorari on the basis of the
Supreme Court’s intervening decision in Mathis v. United
States.60 Pointing to Mathis, Steiner argued that his 1993
Pennsylvania burglary conviction was no longer categorically
a crime of violence. Without the enhancement, Steiner’s base
offense level would have been 14, not 20, thereby yielding a
sentencing range of 37 to 46 months’ imprisonment—a range
of possibilities all markedly below the 87-month within-
Guideline sentence he had actually received.

      As instructed by the Supreme Court’s GVR order, we
now consider the application of Mathis to Steiner’s sentence.
Although the parties agree on Mathis’s effect, it is not for
them to say. Rather, “[t]his question . . . is one for the
courts—not the parties—to decide.”61

       Mathis is the latest in the Supreme Court’s series of
opinions on how prior convictions can be used as predicate
“violent felonies” under the Armed Career Criminal Act
(“ACCA,” 18 U.S.C. § 924(e)), precedent that generally
applies also to “crimes of violence” enhancements under the
Guidelines. 62      Mathis further refined the Court’s
jurisprudence about when, in applying an elements-based
enhancement or analysis, a court may use the “modified
categorical approach”—appropriate for statutes that are
“divisible,” listing elements in the alternative or describing

60
     136 S. Ct. 2243 (2016).
61
  United States v. Calabretta, 831 F.3d 128, 133 (3d Cir.
2016) (citing Sibron v. New York, 392 U.S. 40, 58 (1968)).
62
  See United States v. Brown, 765 F.3d 185, 189 n.2 (3d Cir.
2014).




                               29
separate crimes, and which is employed to determine what
crime a defendant was actually convicted of—instead of the
“categorical approach,” to which we turn when a statute is not
divisible.63

        In Mathis, the Supreme Court analyzed an Iowa
burglary statute that prohibited unlawful entry into not just
“buildings or other structures”—which is the “generic”
federal definition of burglary64—but also into “land, water, or
air vehicle[s].” 65 The Court explained that the Iowa statute
laid out not separate elements, but alternative ways of
satisfying a single locational element; “the statute defines one
crime, with one set of elements, broader than generic
burglary.”66 Because a “state crime cannot qualify as an
ACCA predicate if its elements are broader than those of a
listed generic offense,” a conviction under Iowa’s burglary
statute could not suffice under the proper elements-based
categorical approach. 67 The District Court had erred by using
a “modified categorical approach” instead, treating the
statute’s separate means of committing the offense as if they
were elements. The District Court therefore looked at the



63
   See Singh v. Att’y Gen., 839 F.3d 273, 278-79 (3d Cir.
2016) (discussing the categorical and modified categorical
approaches post-Mathis in the context of an immigration
case).
64
     See Mathis, 136 S. Ct. at 2248, 2250 (citations omitted).
65
     Id. at 2250 (quoting Iowa Code § 702.12 (2013)).
66
     Id.
67
     Id. at 2251.




                                 30
“records of [Mathis’s] prior convictions [to] determin[e] that
he had burgled structures, rather than vehicles.”68

       The relevant 1992 Pennsylvania statute has many of
the same features as the Iowa statute discussed in Mathis.
The Pennsylvania statute defined burglary as “enter[ing] a
building or occupied structure, or separately secured or
occupied portion thereof, with intent to commit a crime
therein, unless the premises are at the time open to the public
or the actor is licensed or privileged to enter.” 69 “Occupied
structure,” addressed one section earlier, meant “[a]ny
structure, vehicle or place adapted for overnight
accommodation of persons, or for carrying on business
therein, whether or not a person is actually present.” 70

       The question Mathis tells us to ask—are these alternate
means or alternate elements?—can be resolved by reference
to “authoritative sources of state law” or, if necessary, “the
record of a prior conviction itself . . . for the sole and limited
purpose of determining whether” we confront means or



68
     See id. at 2250, 2253.
69
   18 Pa. Cons. Stat. § 3502(A) (1992). Pennsylvania’s
burglary statute has been amended several times since 1992,
with the most recent amendment taking effect in early
January 2017. See An Act Amending Titles 18 (Crimes and
Offenses) and 42 (Judiciary and Judicial Procedure) of the
Pennsylvania Consolidated Statutes, 2016 Pa. Laws 158. We
do not today formally reach Mathis’s effect on convictions
under the amended versions of the burglary statute.
70
     18 Pa. Cons. Stat. § 3501 (1992).




                                31
elements. 71 In this case, the 1993 Pennsylvania information
charged Steiner with “feloniously . . . enter[ing] a building or
occupied structure, or separately secured or occupied portion
thereof, with intent to commit a crime therein,” although the
information did identify the specific “location” immediately
following. 72 To the extent this is equivocal, we note that
Pennsylvania’s model criminal jury instructions, albeit for the
current version of the statute, “do[] not require the jury to
unanimously agree on the nature of the location; it can be a
building, or occupied structure, or a separately secured or
occupied portion of a building or structure.”73 By contrast, it
appears that jury findings are generally required for a defense
pertaining to appropriate grading of the burglary offense,
namely whether the structure was not adapted for overnight
accommodation and was not occupied. 74 The Pennsylvania
Supreme Court has also referred to its burglary statute as an
“expan[sion]” of the “common law definition” of the crime,
enacted to “recognize[] that non-privileged entries into any of
these areas is a burglary because such entries pose a threat of
violence to persons.”75 This discussion of the broad scope of
71
   Mathis, 136 S. Ct. at 2256-57 (internal quotation marks and
citation omitted).
72
     See Information, ECF No. 144-1.
73
   United States v. Harris, No. 1:CR-06-0268, ___ F. Supp.
3d ___, 2016 WL 4539183, at *11 (M.D. Pa. Aug. 31, 2016)
(citing Pennsylvania Suggested Standard Criminal Jury
Instructions § 15.3502).
74
   See 18 Pa. Cons. Stat. § 3502(C)(1) (1992); Commonwealth
v. Conaway, 105 A.3d 755, 763 (Pa. Super. Ct. 2014), appeal
denied, 118 A.3d 1107 (Pa. 2015).
75
     Commonwealth v. Rolan, 549 A.2d 553, 559 (Pa. 1988).




                              32
burglary as a single crime that reaches multiple kinds of
unlawful entry strongly suggests that the statute’s breadth
turns on means, not elements.

       We therefore hold that these are alternative means of
committing the core burglary element. 76 The statute is not
divisible and, after Mathis, a categorical approach, rather than
a modified categorical approach, must be used.

        We pause to recognize that other Courts of Appeals
have, after Mathis, held that various state burglary statutes set
out different elements, and not different means, based on the
wording of particular statutes. The Iowa burglary statute
analyzed in Mathis defines burglary as the entering of “an
occupied structure,” a term it then defines elsewhere. 77 In
other words, the Iowa burglary statute itself makes reference
to a single locational element without employing a disjunctive
list. In United States v. Gundy, by contrast, the Eleventh

76
   This comports, to an extent, with our 1996 decision in
United States v. Bennett, 100 F.3d 1105 (3d Cir. 1996).
Reaching the same statutory language, we held that the
Pennsylvania definition of occupied structure “makes
Pennsylvania’s burglary statute broader than Congress’s
generic view of burglary,” as it reaches scenarios such as the
unauthorized entry of a car. Id. at 1109. While at the time we
thought that the statute’s breadth authorized use of what
would now be called the modified categorical approach, see
id. at 1110, it is now clear under Mathis that alternative
means, rather than alternative elements, do not render the
statute divisible.
77
   See Iowa Code §§ 713.1 (defining burglary), 702.12
(defining occupied structure).




                               33
Circuit confronted a Georgia statute that listed what the court
described as “three subsets of different locational elements,
stated in the alternative and in the disjunctive.” 78 Informed
by an analysis of Georgia state opinions about burglary, the
divided Eleventh Circuit panel determined that the statute
listed alternative elements, not means, and was thus
divisible.79 Other courts have reached similar conclusions. 80

        Based on our discussion above of Pennsylvania law
and practice, as well as the substantial overlap between
“building” and “occupied structure” under the statutory
definition, we believe that we are on solid footing.
Nevertheless, the divergence of outcomes after Mathis
suggests that the “elements or means” inquiry is not quite as
easy as the Supreme Court thought, not the least because state
legislatures and state courts do not draft their laws and craft
their decisions with this particular distinction in mind.

       Returning to our analysis, we next compare the
Pennsylvania statute to the generic offense of “burglary of a
dwelling.” We have previously defined “dwelling” by

78
  842 F.3d 1156, 1166-67 (11th Cir. 2016) (citing Ga. Code
Ann. § 16-7-1(a) (2011)).
79
     See id. at 1167-68.
80
  See, e.g., United States v. Sykes, 844 F.3d 712, 715-16 (8th
Cir. 2016) (coming to a similar outcome); United States v.
Uribe, 838 F.3d 667, 670 (5th Cir. 2016) (same). But see
United States v. Edwards, 836 F.3d 831, 834-38 (7th Cir.
2016) (finding that disjunctive parts of a statute were means,
not elements, while observing that state decisions and
practices did not definitively answer the question).




                              34
reference to the then-current Sixth Edition of Black’s Law
Dictionary: a “building or portion thereof, a tent, a mobile
home, a vehicle or other enclosed space which is used or
intended for use as a human habitation, home or residence.” 81
The Pennsylvania statute plainly sweeps more broadly than
“burglary” narrowed to dwellings. 82

       Under the categorical approach, then, a conviction
under the Pennsylvania burglary statute in question is not a
predicate § 4B1.2 “crime of violence.”83 Thus, Steiner’s

81
   United States v. McClenton, 53 F.3d 584, 587 (3d Cir.
1995) (emphasis omitted) (quoting Dwelling, Black’s Law
Dictionary (6th ed. 1990)). Beginning with the Seventh
edition of Black’s Law Dictionary, “Dwelling” falls under the
main entry of “Dwelling-house,” of which it is considered to
be an abbreviation. The “Criminal Law” meaning of
“Dwelling-house” is currently defined as follows: “A
building, a part of a building, a tent, a mobile home, or
another enclosed space that is used or intended for use as a
human habitation.” Dwelling-house, Black’s Law Dictionary
(10th ed. 2014).
82
   It appears to be broader than plain generic burglary, too.
For instance, the unlawful entry of a river gambling boat,
which is a “vehicle” adapted for “carrying on business
therein,” seems to fall under the Pennsylvania statute’s
definition of “burglary,” but not the generic federal offense as
articulated by the Supreme Court.
83
   We have previously held that the “residual clause” of
§ 4B1.2 is unconstitutionally vague. See Calabretta, 831
F.3d at 133-34. The precise question of the clause’s validity
is now pending before the United States Supreme Court in
Beckles v. United States, No. 15-8544. If it is reinstated by




                              35
1993 burglary conviction should not have been used to
enhance his sentence. As the government concedes plain
error,84 we will vacate the judgment of sentence and remand
for expedited resentencing.

       We must reach one final matter before closing: Steiner
contends that he has already served a term of imprisonment
longer than would be authorized by a Guidelines range
without the “crime of violence” enhancement. As we noted
above, at offense level 14 and with a criminal history of VI,
Steiner’s range would be 37–46 months instead of the 70–87
months he faced before. Although Steiner does not provide
us with the Bureau of Prisons information he used to compute
the months he has already served—he was serving a state
sentence when the underlying federal criminal proceedings
began, and there is no obvious indication on the docket of
when he was formally committed to the Bureau of Prisons—it
appears likely that he has already been in the custody of the
Bureau of Prisons for over 46 months, and the government
does not dispute his characterization of his time served. We
therefore will order that Steiner be released from custody,
subject to the conditions of supervised release imposed in the
District Court’s original judgment, pending expedited
resentencing.




the Supreme Court, the District Court should not consider it
on remand, as the government has not argued that it should
apply.
84
  See United States v. Knight, 266 F.3d 203, 206-09 & n.7
(3d Cir. 2001).




                             36
                     IV. CONCLUSION

       For the reasons set forth above, we will affirm the
District Court’s judgment of conviction, vacate its judgment
of sentence, grant Steiner’s motion for remand, and remand
for expedited resentencing. Steiner is ordered released
pending his resentencing.




                            37
