          United States Court of Appeals
                        For the First Circuit


No. 16–1140

                      UNITED STATES OF AMERICA,

                              Appellee,

                                  v.

                       YRVENS BAIN, a/k/a "E,"

                        Defendant, Appellant.


          APPEAL FROM THE UNITED STATES DISTRICT COURT
                FOR THE DISTRICT OF MASSACHUSETTS

              [Hon. Indira Talwani, U.S. District Judge]


                                Before

                   Torruella, Kayatta, and Barron,
                           Circuit Judges.


     Christine DeMaso, Assistant Federal Public Defender, for
appellant.
     Randall E. Kromm, Assistant United States Attorney, with whom
William D. Weinreb, Acting United States Attorney, was on brief,
for appellee.


                           October 13, 2017
             KAYATTA, Circuit Judge.       The police arrested Yrvens Bain

after   he    emerged    from   a     multi-family     building      in   Malden,

Massachusetts.     During the search incident to that arrest, they

found a set of keys in his possession.               The police tried these

keys on the front door of the multi-family building and on the

doors to three apartments inside--one on the first floor, two on

the second floor.       The keys opened the door to one of the units on

the second floor.        The police included this information in an

application for a warrant to search that unit. The warrant issued,

and the search produced a firearm and over twenty-six grams of

heroin mixed with fentanyl.          Bain moved to suppress that evidence.

He argued, among other things, that the officers conducted an

unlawful search by turning his key in the locks to identify the

unit to search, and that there was no probable cause to issue a

warrant to search the unit without that identification.

             The district court denied Bain's motion.          The court also

subsequently denied his motion in limine to exclude a credit-card-

making machine found during the search. At trial, a jury convicted

Bain on two counts of distribution of heroin, see 21 U.S.C.

§   841(a)(1),   one    count   of    possessing     heroin   with    intent   to

distribute, see id., and one count of possessing a firearm and

ammunition after a conviction for a felony punishable by over one

year in prison, see 18 U.S.C. § 922(g)(1).               At sentencing, the

district court applied the fifteen-year mandatory minimum sentence


                                      - 2 -
under the Armed Career Criminal Act (ACCA), see id. § 924(e). Bain

appeals the rulings on his motion to suppress, his motion in

limine, and his sentence.         While we agree with Bain that the

officers conducted an unlawful search by testing the key in the

lock of the unit in which he was staying, we nevertheless affirm

the denial of the motion to suppress because in searching the

apartment the officers relied in good faith on the intervening

warrant.   We also affirm Bain's conviction and sentence.

                                      I.

                                      A.

             Brian   Connerney,   a    detective   in   the   Arlington,

Massachusetts Police Department and a Task Force Agent with the

Drug Enforcement Administration (DEA), signed both affidavits

supporting the search warrant application.1             We describe the

relevant information contained in those affidavits.

             In early 2014, the DEA began investigating Bain.        At

the time, Bain had four prior convictions for "drug trafficking

offenses."     All four involved cocaine and the most recent had

occurred in 2007.      By 2014, Bain's six-year prison sentence for



     1 The search warrant application included both a search
warrant affidavit and the affidavit previously submitted to
support the application for the criminal complaint. See United
States v. Bain, 155 F. Supp. 3d 107, 112 n.1 (D. Mass. 2015). The
district court drew from both affidavits in evaluating whether
there was probable cause to issue the search warrant.      See id.
Bain has not objected to this approach.


                                  - 3 -
that conviction had ended and his five-year probation term had

just begun.

               As part of the investigation, a cooperating witness made

two controlled buys from Bain.           In connection with both controlled

buys,       officers   searched   the    cooperating   witness   beforehand,

provided him with a recording device and the cash used to purchase

the drugs, and retrieved the drugs from him afterwards.

               The cooperating witness made the first controlled buy on

February 26, 2014.        After texting Bain to request $100 worth of

heroin, the cooperating witness picked Bain up at an apartment

complex in Waltham, Massachusetts, next to which Bain's car was

parked.2      The cooperating witness paid $100 in cash for a baggie

containing 0.80 grams of a mixture of heroin and fentanyl.

               Three days later, police responded to a report of a fight

in progress at the same apartment complex in Waltham.              Bain had

been living in his brother's apartment in that complex, the two

men had been in an argument, and Bain had punched his brother.

These events precipitated an assault and battery charge against

Bain, which landed him in police custody until March 17.               When

Bain was released, he informed his probation officer that he



        2
       Connerney identified Bain's car as a brown Cadillac DeVille
with a Massachusetts license plate.     The car was registered in
Bain's name at an address in Arlington. Connerney confirmed that
a police report in a prior case involving Bain reported him driving
the same vehicle in July 2011.


                                        - 4 -
planned to live at his mother's residence in Arlington.        But

Connerney never saw Bain at that residence and never saw his car

parked outside.

          The day after Bain's release, he texted the cooperating

witness, saying, "I was away for awhile but now I'm back hit me up

everything's good."   After the cooperating witness again requested

$100 worth of heroin, Bain directed him to "Waite st." in "Malden."

Bain once again got into the cooperating witness's car and sold

him a baggie containing heroin for $100 in cash.   The cooperating

witness drove around the block and let Bain out of the car on

Webster Street.

          On several subsequent occasions, Connerney and other

officers involved in the investigation observed Bain's car parked

on Webster Street in Malden, near the intersection with Laurel

Street.   On March 28 at 2:35 P.M., officers in the Malden Police

Department observed Bain park on Webster Street, walk to Laurel

Street, and enter 131 Laurel Street.   Roughly ten hours later, at

12:30 A.M. on March 29, Connerney observed Bain's car still parked

on Webster Street.

          Two days later, with a signed criminal complaint in hand,

officers went to 131 Laurel Street to arrest Bain.   They saw Bain

emerge through the front door of 131 Laurel Street, walk to his

car around the corner on Webster Street, and get inside. As agents

approached the car, Bain locked his doors and swallowed something.


                               - 5 -
Agents removed him from the car, placed him under arrest, conducted

a search incident to arrest, and seized credit cards and a set of

keys from his person.

          The agents used the keys they had seized from Bain to

open the front door of 131 Laurel Street.   Connerney described the

building located at 131 Laurel Street as follows:

          131 Laurel Street is a two and a half story
          home located near the intersection of Laurel
          Street   and   Webster   Street   in   Malden,
          Massachusetts.    A hedge surrounds the front
          yard. . . .     The main entrance is a large
          wooden door with a circular window and is
          accessed by a set of stairs rising from a
          sidewalk running alongside Laurel Street. At
          the front door, there are four black mail
          boxes, two on each side of the door. [Unit D3]
          is located on the second floor . . . .
          [Unit] D is accessed by walking up the main
          staircase to the second floor landing.     The
          door is on the right hand side.      It is the
          only door on the right hand side of the second
          floor landing.

Bain's name was not on any of the four mailboxes.

          After entering the building, the agents "tried the keys

in one door on the first floor and two doors on the second floor."

The keys fit the door to unit D.   They entered unit D and conducted

a "protective sweep to make sure no one else was inside."       The

unit was empty.   During the protective sweep, agents observed mail



     3  We refer to this location as "unit D" rather than
"apartment D" because the unit was in fact a condominium, which
the tenant rented from someone who owned only that single
condominium.


                               - 6 -
addressed    to   "131    Laurel    Street,    Apartment   D,      Malden,

Massachusetts," a parking ticket issued to Bain's car on a chair

in one of the bedrooms, and a safe in the same bedroom.

            Armed with the information that the keys seized from

Bain opened the main door to 131 Laurel Street and the door to

unit D, the officers sought a warrant to search unit D. In addition

to the information summarized above, the affidavit used to obtain

the warrant contained a series of statements, based on Connerney's

training and experience, establishing that it was reasonable to

expect that Bain kept drugs, tools of the trade, cash, and records

in the place where he resided.

            Upon review of the affidavit, a federal magistrate judge

issued a warrant to search unit D for a long list of items,

including records relating to the purchase and sale of controlled

substances, cash derived from the sale of controlled substances,

documents relating to the control of unit D, photographs of

relevant    property,    and   personal    electronic   devices.       The

subsequent search produced several key pieces of evidence against

Bain.   In one of the bedrooms, the police found a parking ticket

for Bain's car (the same one they saw during their warrantless

entry into the unit), $300 in cash, and, in a trash can, used latex

gloves and sandwich bags with the corners torn off.         In a closet

of that bedroom, they found several cards with Bain's name on them:

a Massachusetts driver's license, a social security card, an


                                   - 7 -
identification card, an auto insurance card, a MassHealth card,

and a AAA card. They also found a box in the closet, originally

for size twelve Timberland shoes, that contained plastic bags,

latex gloves, a digital scale, a bag containing 26.8 grams of a

mixture of heroin and fentanyl, a razor blade, assorted pills, a

handgun    with   an    obliterated    serial   number,   and   a    magazine

containing bullets.       In the closet of the other bedroom, police

found a credit-card-making machine and boxes of blank cards, men's

clothing, a pair of Timberland boots, several boxes of sneakers

(sizes eleven to twelve), and sneakers containing around $7000 in

cash.    Five of the $20 bills in the shoes came from the government

funds that the cooperating witness had used in the March 21

controlled buy.     At trial, the government submitted evidence that

Bain wore size twelve shoes.

            The district court denied Bain's motion to suppress both

the fact that the keys found in his possession opened the door to

unit D and the items found during the search pursuant to the

warrant.     See United States v. Bain, 155 F. Supp. 3d 107, 125

(D. Mass. 2015).       In so doing, the court agreed with Bain that the

turning of the key in the lock of unit D and the ensuing "protective

sweep"     were   unreasonable    searches.       See     id.   at    120–23.

Nevertheless, finding that the officers relied in good faith on

precedent when turning the key, see id. at 121–22, the court took

account of the fact that the key fit the lock of unit D when


                                      - 8 -
concluding that there was probable cause for a warrant to search

unit D, see id. at 124.      Bain challenges that ultimate ruling, and

the government challenges the predicate ruling that testing the

key in the lock was an unreasonable search.4                The government also

argues,   as    a   threshold   matter,      that    Bain    lacked    sufficient

connection to unit D to challenge the search.

                                       B.

           As   we   will   explain,    we    find   that    Bain     did   have   a

sufficient connection with unit D to mount an unfettered challenge

to the search of that unit.        In a matter of first impression in

this circuit, we also find that the turning of the key in the lock

of unit D was an unreasonable, warrantless search unsupported by

any clear precedent, and that without the information obtained by

turning the key, there was no probable cause to issue a warrant to

search unit D.      Nevertheless, as we will also explain, because the

officers were entitled to rely in good faith on the warrant, the

information secured in executing that warrant need not have been

suppressed.5


     4 The district court also ruled that no exigent circumstances
rendered the entry into unit D reasonable.     See id. at 122–23.
The court therefore did not consider any evidence obtained from
that entry when evaluating the warrant. See id. The government
does not challenge this ruling.
     5 We could skip all but the last finding by merely assuming
answers to the other issues favorable to Bain.    We eschew that
more limited approach in order to clarify our case law on the
predicate issues in a case in which we have the benefit of very
good briefs by both sides. See United States v. Leon, 468 U.S.


                                   - 9 -
                                             1.

             We    start     by    briefly      describing       the       tests    used    to

determine whether a search has occurred within the meaning of the

Fourth     Amendment.            Under    the       reasonable       expectations       test

described in Justice Harlan's concurring opinion in Katz v. United

States,    389     U.S.    347     (1967),      a      search   occurs      whenever       the

government      intrudes     upon    any     place       in   which    a    person    has    a

"reasonable expectation of privacy."                      Id. at 360 (Harlan, J.,

concurring).       There are two steps involved in applying this test.

"First,    we     ask    whether    the    individual,          by    his    conduct,      has

exhibited an actual expectation of privacy; that is, whether he

has shown that he '[sought] to preserve [something] as private.'"

Bond v. United States, 529 U.S. 334, 338 (2000) (alterations in

original) (quoting Smith v. Maryland, 442 U.S. 735, 740 (1979)).

"Second,    we     inquire       whether   the         individual's        expectation      of

privacy    is     one     that     society        is    prepared      to    recognize       as

reasonable."       Id.

             The Supreme Court has also employed common-law trespass

concepts to determine when a search has occurred.                                  Under the


897, 924 (1984) ("There is no need for courts to adopt the
inflexible practice of always deciding whether the officers'
conduct manifested objective good faith before turning to the
question whether the Fourth Amendment has been violated.
Defendants seeking suppression of the fruits of allegedly
unconstitutional searches or seizures undoubtedly raise live
controversies which Art. III empowers federal courts to
adjudicate.").


                                          - 10 -
common-law trespassory test described in Florida v. Jardines, 133

S. Ct. 1409 (2013), "[w]hen 'the Government obtains information by

physically intruding' on persons, houses, papers, or effects, 'a

"search" within the original meaning of the Fourth Amendment' has

'undoubtedly occurred.'"            Id. at 1414 (quoting United States v.

Jones, 565 U.S. 400, 404-05 (2012)); see also Grady v. North

Carolina, 135 S. Ct. 1368, 1370 (2015) (per curiam).                   This test

supplements, rather than replaces, the Katz test.                 See Jardines,

133 S. Ct. at 1417 ("The Katz reasonable-expectations test 'has

been added to, not substituted for,' the traditional property-

based understanding of the Fourth Amendment, and so is unnecessary

to consider when the government gains evidence by physically

intruding on constitutionally protected areas." (quoting Jones,

565 U.S. at 409)).

             In    Jardines    itself,   the   Supreme    Court   employed   the

common-law trespassory test to determine that a physical intrusion

into the "curtilage" of a home constituted a search under the

Fourth Amendment even though no intrusion into the home had

occurred.         See   id.   at   1417–18.    The    curtilage   is   the   area

"immediately surrounding and associated with the home," and it is

"part of the home itself for Fourth Amendment purposes."                  Id. at

1414 (quoting Oliver v. United States, 466 U.S. 170, 180 (1984)).

"This area around the home is 'intimately linked to the home, both

physically        and    psychologically,'      and      is   where     'privacy


                                      - 11 -
expectations are most heightened.'"              Id. at 1414-15 (quoting

California v. Ciraolo, 476 U.S. 207, 213 (1986)).

            Under Jardines, a physical intrusion into a protected

area that results in the acquisition of information only fails to

constitute a search if that intrusion is permitted by a license.

"[T]he knocker on the front door is treated as an invitation or

license to attempt an entry, justifying ingress to the home by

solicitors, hawkers and peddlers of all kinds."                    Id. at 1415

(quoting Breard v. Alexandria, 341 U.S. 622, 626 (1951)).                "This

implicit license typically permits the visitor to approach the

home   by   the   front   path,   knock   promptly,   wait   briefly    to    be

received, and then (absent invitation to linger longer) leave."

Id.    The police may take advantage of this license to "approach a

home and knock" without a warrant.           Id. at 1416.    However, "[t]he

scope of a license--express or implied--is limited not only to a

particular area but also to a specific purpose."             Id.    The police

behavior considered in Jardines--"introducing a trained police dog

to explore the area around the home in hopes of discovering

incriminating evidence," id.--exceeded the implicit license.                 The

Court provided other examples of behavior that would also exceed

the license:      "exploring the front path with a metal detector" or

"marching [a] bloodhound into the garden before saying hello and

asking permission."       Id.




                                    - 12 -
                                 2.

          The government contends that Bain lacks full Fourth

Amendment rights in unit D.     The parties refer to this issue as

one of "standing" to assert Fourth Amendment rights.            Although

courts sometimes use this nomenclature, see United States v.

Stokes, 829 F.3d 47, 51 (1st Cir. 2016), the Supreme Court has

made clear that "definition of [Fourth Amendment] rights is more

properly placed within the purview of substantive Fourth Amendment

law than within that of standing," Rakas v. Illinois, 439 U.S.

128, 140 (1978); see also Stokes, 829 F.3d at 51 n.7.

          Bain was staying in unit D with his girlfriend, who

rented the unit.   The district court found that Bain "was, at the

least, an overnight guest" in unit D.        Bain, 155 F. Supp. 3d at

115. Under Supreme Court precedent, Bain's "status as an overnight

guest is alone enough to show that he had an expectation of privacy

in the home that society is prepared to recognize as reasonable."

Minnesota v. Olson, 495 U.S. 91, 96-97 (1990).       In short, Bain's

status as an overnight guest endowed him with Katz's protection of

a reasonable expectation of privacy in the unit.

          The   government    nevertheless    contends   that     Bain's

interest in the unit as an overnight guest, while sufficient to

secure a reasonable expectation of privacy within the unit, falls

short of the type of property ownership that would allow him to

complain of a trespass within the unit or its curtilage.          Hence,


                               - 13 -
argues the government, an extension of Fourth Amendment interests

derived from Jardines's common-law trespassory test offers no

protection to Bain as an overnight guest.

           We reject this argument that a search defined in part by

an invasion of property rights is a search only as to persons who

could maintain a common law trespass claim.     The property rights

test applied in Jones and Jardines was foreshadowed by Justice

Scalia's concurring opinion in Minnesota v. Carter.    525 U.S. 83,

92-97 (1998) (Scalia, J., concurring).   Justice Scalia stated that

he considered Olson's extension of Fourth Amendment rights to an

overnight guest compatible with the property-based test because

"it is plausible to regard a person's overnight lodging as at least

his 'temporary' residence."   Id. at 96–97.   He explained that this

conclusion is supported by both history and common understanding.

See id. at 95–96 (stating that "[p]eople call a house 'their' home

when legal title is in the bank, when they rent it, and even when

they merely occupy it rent free--so long as they actually live

there").   We agree with this reasoning.      If a living unit is a

person's home under Olson, then the person's Fourth Amendment

protections are not diminished by the temporary nature of the

person's residence.

           Therefore, to the extent that the key-turning is deemed

a Fourth Amendment search because it constituted a trespassory

invasion under Jones and Jardines--a subject that we will next


                              - 14 -
discuss--we see no reason not to apply the amendment's protections

to an overnight guest just as we would to a renter or owner.

                                3.

           Having concluded that Bain has Fourth Amendment rights

in unit D under both the reasonable-expectations test and the

common-law trespassory test, we ask next whether a search occurred.

Bain has argued that there was a search under both tests.

                                a.

           "At the [Fourth] Amendment's 'very core' stands 'the

right of a man to retreat into his own home and there be free from

unreasonable governmental intrusion.'"     Jardines, 133 S. Ct. at

1414 (quoting Silverman v. United States, 365 U.S. 505, 511

(1961)).   There is no reason to expect a different answer when the

home is a rented condominium. See, e.g., Chapman v. United States,

365 U.S. 610, 615 (1961) (rented premises); Johnson v. United

States, 333 U.S. 10, 17 (1948) (hotel room).

           One might reasonably conclude that the inside of the

front door lock is within the home itself because it is within the

outer plane of the home's structure.   Under Jardines, however, all

we need decide is whether the inside of the front door lock is at

least within the home's curtilage.     Under United States v. Dunn,

480 U.S. 294 (1987), "the centrally relevant consideration" in

determining the extent of a home's curtilage is "whether the area

in question is so intimately tied to the home itself that it should


                              - 15 -
be    placed     under    the    home's    'umbrella'      of   Fourth    Amendment

protection."        Id. at 301.           To help answer this question, we

consider four factors:           (1) "the proximity of the area claimed to

be curtilage to the home"; (2) "whether the area is included within

an enclosure surrounding the home"; (3) "the nature of the uses to

which the area is put"; and (4) "the steps taken by the resident

to protect the area from observation by people passing by."                   Id.

               Applying the Dunn factors,6 we conclude that the lock on

the door to unit D is within the unit's curtilage even if it is

not   within     the     unit   itself.7     The   first    factor   is    strongly



       6
       We do not rely on the statement in United States v. Cruz
Pagán, 537 F.2d 554 (1st Cir. 1976), that the curtilage of each
unit in a condominium complex extends only to areas in the
exclusive control of the unit's occupant.       Id. at 558.    This
reasoning was unnecessary to Cruz Pagán's holding, which only
concerned whether the resident of a condominium complex has a
reasonable expectation of privacy in the complex's shared
underground garage. Id. at 557 ("The legal question which we must
resolve is whether the agents' entry into the garage defeated the
reasonable expectation of privacy of any of the appellants.").
The court only raised the issue of curtilage on the "[a]ssum[ption]
that concepts of curtilage have some relevancy to the Katz
inquiry," id. at 558, and, even then, the only conclusion necessary
to the court's holding was that the garage was not part of the
unit's curtilage.     The broader language about whether other
portions of the condominium complex were within the unit's
curtilage was therefore dicta. On top of that, Cruz Pagán dates
from before Dunn and did not consider any of the factors deemed
significant by Dunn.    For these reasons, we do not think Cruz
Pagán's broad declaration about the scope of a condominium unit's
curtilage binds us.
       7
       Thus, we need not address the government's argument that
unit D's tenant lacked a possessory interest in the door of the
unit.


                                      - 16 -
satisfied.     Very few, if any, things are more proximate to the

interior of a home than is a lock on the door to the home.

Certainly, too, the interior of the lock, from which the crucial

information was gathered, is within or adjacent to the enclosure

of the door's outer face.       The uses of the lock also strongly weigh

in favor of finding its penetration to be a search.                The lock,

after all, is used precisely to bar unwelcome entry and invasion

of privacy.    Finally, the very design of a lock hides its interior

from examination.     All in all, we have no difficulty finding that

the inside of the lock on the door of a home "should be placed

under the home's 'umbrella' of Fourth Amendment protection."                Id.

                                       b.

             Under Jardines, a physical intrusion into the curtilage

to obtain information (here, putting the key in the lock to see if

it fit) is a search unless it is within the "implicit license"

which "typically permits the visitor to approach the home by the

front path, knock promptly, wait briefly to be received, and then

(absent invitation to linger longer) leave."            133 S. Ct. at 1415.

To   be   clear,   assuming   that   the    police   were   lawfully   in   the

building, they could approach the door and knock without being

deemed to have conducted a search.            But walking up to the door of

a home and trying keys on the lock does not differ markedly from

walking up with a trained police dog to sniff around the door.

Paraphrasing Jardines:        To find a visitor knocking on the door is


                                     - 17 -
routine (even if sometimes unwelcome); to find that same visitor

trying a series of keys on the door's lock "would inspire most of

us to--well, call the police."      133 S. Ct. 1416.   As in Jardines,

"the background social norms that invite a visitor to the front

door do not invite him there to conduct a search."      Id.    In short,

a search occurred.

                                    c.

          The   government     nevertheless   argues    that    we   are

foreclosed from holding that trying the key on the door to unit D

constituted a "search" by United States v. Lyons, 898 F.2d 210

(1st Cir. 1990), and United States v. Hawkins, 139 F.3d 29, 31

(1st Cir. 1998).     We disagree.    Lyons and Hawkins concerned the

use of keys on storage container padlocks. Lyons, 898 F.2d at 212;

Hawkins, 139 F.3d at 31.   Storage container padlocks are "effects"

under the Fourth Amendment.    See Lyons, 898 F.2d at 219 (Woodlock,

J., dissenting); cf. Oliver, 466 U.S. at 177 n.7 ("The Framers

would have understood the term 'effects' to be limited to personal,

rather than real, property."); United States v. Jacobsen, 466 U.S.

109, 114 (1984) (letters and sealed packages are effects); United

States v. Place, 462 U.S. 696, 705–06 (1983) (luggage is an

effect); Jones, 565 U.S. at 404 ("It is beyond dispute that a

vehicle is an 'effect' as that term is used in the [Fourth]

Amendment.").   The Fourth Amendment protects effects markedly less

than it protects houses.     See Jardines, 133 S. Ct. at 1414 ("When


                                - 18 -
it    comes   to     the    Fourth    Amendment,        the    home       is   first     among

equals."); Chambers v. Maroney, 399 U.S. 42, 52 (1970) ("[F]or the

purposes      of    the    Fourth     Amendment     there      is     a    constitutional

difference between houses and cars.").                     Indeed, before Jardines

the Supreme Court held that dog-sniffs of certain effects are not

searches under the Fourth Amendment.                     See Illinois v. Caballes,

543 U.S. 405, 409 (2005) (dog sniff of car); Place, 462 U.S. at

707    (dog   sniff        of    luggage).       Jardines      reached         a      different

conclusion because it concerned a house rather than an effect.

Justice Kagan's concurrence in Jardines explained that Caballes

did not control because the Court had "held, over and over again,

that people's expectations of privacy are much lower in their cars

than in their homes."                 133 S. Ct. at 1419 n.1 (Kagan, J.,

concurring).        Likewise, here, our statements in Lyons and Hawkins

concerning         the    insertion    of    keys       into   padlocks          on    storage

containers do not control whether testing a key on the lock to a

home is a search.

              The government also points to other circuit courts that

have reached the conclusion that testing a key on a lock is not a

search. Several of these cases involve the use of keys to identify

the   owners       of    cars,    which   are,     as    we    have       just     explained,

distinguishable.           See United States v. $109,179 in U.S. Currency,

228 F.3d 1080, 1087-88 (9th Cir. 2000) (car door); United States

v. DeBardeleben, 740 F.2d 440, 445 (6th Cir. 1984) (car door).


                                          - 19 -
The cases that involve testing keys on the doors to apartments are

also either distinguishable or unconvincing.        United States v.

Salgado, 250 F.3d 438 (6th Cir. 2001), does involve testing a key

in an apartment door.     Salgado, however, was decided well before

Jardines, and thus, at the time, plausibly rested on an observation

that the lock on the apartment door (in an unlocked hallway) was

"just as accessible to the public . . . as an automobile lock."

Id. at 457.      In finding that the Fourth Amendment protects the

curtilage of a home from unlicensed searches even though it is

readily accessible to the public, Jardines eliminated that basis

for Salgado's holding.     In United States v. Moses, 540 F.3d 263

(4th Cir. 2008), the Fourth Circuit held that "the discrete act of

inserting the key into the lock and discovering whether or not it

fit did not offend the Fourth Amendment."     Id. at 272.   The opinion

contains no reasoning or analysis. It merely cites Salgado, Lyons,

$109,179 in U.S. Currency, and United States v. Concepcion, 942

F.2d 1170 (7th Cir. 1991). The first three cases we have discussed

and distinguished above.     Concepcion actually held that testing

keys in an apartment door was a search, albeit one that was not

unreasonable (a finding we will discuss in the next section of

this opinion).     See 942 F.2d at 1172-73.    This case law provides

no persuasive support for the government's position, and we find

ourselves comfortable in concluding that testing the key in the

lock of unit D was a search.


                                - 20 -
                                        4.

          Having concluded that a search occurred when the police

placed and turned a key in the lock of the door to unit D, we must

determine whether that search was reasonable.              The reasonableness

of a search is a question of law, which we review de novo.                   See,

e.g., United States v. Samboy, 433 F.3d 154, 158 (1st Cir. 2005).

                                        a.

          The starting point for the reasonableness analysis is

the "basic principle of Fourth Amendment law . . . that searches

and seizures inside a home without a warrant are presumptively

unreasonable."      Kentucky v. King, 563 U.S. 452, 459 (2011).              And,

as we have explained, Jardines treats unlicensed intrusions into

the home's curtilage as intrusions into the home, see 133 S. Ct.

at 1414, hence this presumption applies here even if we do not

deem the door lock to be within the home itself.                "But . . . this

presumption may be overcome in some circumstances because [t]he

ultimate touchstone of the Fourth Amendment is reasonableness."

King, 563 U.S. at 459 (alteration in original) (quoting Brigham

City v. Stuart, 547 U.S. 398, 403 (2006)).              The main exceptions to

this   rule   for    house      searches     arise   in    cases   of   exigent

circumstances,      see   id.    at   460    (listing     the   exceptions    for

"emergency aid," for "hot pursuit" of a fleeing suspect, and for

preventing "the imminent destruction of evidence"), and consent,

see Georgia v. Randolph, 547 U.S. 103, 109 (2006).


                                      - 21 -
            The   exigent    circumstances     exception    to   the   warrant

requirement is a specific application of what the Supreme Court

has described as a more general rule:              "When faced with special

law enforcement needs, diminished expectations of privacy, minimal

intrusions, or the like, the Court has found that certain general,

or individual, circumstances may render a warrantless search or

seizure reasonable."         Illinois v. McArthur, 531 U.S. 326, 330

(2001); see also Maryland v. King, 133 S. Ct. 1958, 1969 (2013)

(relying on same principle for search of person); United States v.

Knights, 534 U.S. 112, 121 (2001) (similar for search of house);

Maryland v. Buie, 494 U.S. 325, 331 (1990) (similar).                  When a

warrantless search or seizure is not per se unreasonable, the court

may    "balance   the   privacy-related      and   law   enforcement-related

concerns to determine if the intrusion was reasonable."            McArthur,

531 U.S. at 331. As the name suggests, the balancing test requires

assessing both the privacy interests and the law enforcement

interests involved. See Arizona v. Hicks, 480 U.S. 321, 327 (1987)

(stating that a seizure is justified on less than probable cause

when    "the   seizure      is   minimally    intrusive    and   operational

necessities render it the only practicable means of detecting

certain types of crime").          The cases that apply this balancing

test generally replace the warrant requirement with some other

requirement, such as individualized suspicion at the level of

reasonable suspicion or probable cause, see, e.g., Pennsylvania v.


                                    - 22 -
Labron,   518   U.S.     938,   940–41    (1996)    (per   curiam)   (allowing

warrantless search of automobile with probable cause); Place, 462

U.S. at 706 (allowing temporary seizure of luggage based on

reasonable suspicion); Terry v. Ohio, 392 U.S. 1, 27 (1968)

(allowing stop-and-frisk with reasonable suspicion), or with a

limitation on the discretion of officers conducting the searches,

see, e.g., King, 133 S. Ct. at 1969–70 (allowing mandatory buccal

swabs of people arrested for serious crimes); Mich. Dep't of State

Police v. Sitz, 496 U.S. 444, 453–55 (1990) (allowing mandatory

stops at drunk driver checkpoint).            When performing this balancing

test, a court must look to the "totality of the circumstances."

Missouri v. McNeely, 133 S. Ct. 1552, 1559 (2013) (citing, inter

alia, McArthur, 531 U.S. at 331).             The government has the burden

of proving that a warrantless search was nevertheless reasonable.

See Vale v. Louisiana, 399 U.S. 30, 34 (1970) ("[O]nly in 'a few

specifically established and well-delineated' situations may a

warrantless     search     of   a   dwelling       withstand   constitutional

scrutiny, even though the authorities have probable cause to

conduct it.     The burden rests on the State to show the existence

of such an exceptional situation." (citation omitted)).

                                         b.

           The sum total of the government's argument that the

search of unit D's lock was reasonable is (1) repeating that the

intrusion involved in testing a key in a lock is "minor" or


                                    - 23 -
"minimal," and (2) providing a string citation to a series of cases

concluding that testing a key in a lock does not require a warrant

or probable case.   Two of the cases the government cites, Lyons

and $109,179 in U.S. Currency, involve locks on effects rather

than homes, as discussed above.   One of the cases the government

cites, Moses, contains no analysis, as we have also mentioned.   We

focus, therefore, on the government's other two cited cases:

United States v. Thompson, 842 F.3d 1002 (7th Cir. 2016), and

Commonwealth v. Alvarez, 661 N.E.2d 1293 (Mass. 1996).     Both of

these cases rely for their reasoning on an earlier Seventh Circuit

case, United States v. Concepcion, 942 F.2d 1170 (7th Cir. 1991).

See Thompson, 842 F.3d at 1008; Alvarez, 661 N.E.2d at 1302 & n.10.

We do not think the reasoning of Concepcion adequately supports

the government's argument as to unit D.8

          In Concepcion, the Seventh Circuit held that the use of

a key in the lock of an apartment was a search, but that the search

was reasonable without a warrant or probable cause.   See 942 F.2d

at 1172–73.   The court reached the latter conclusion because

          [w]here [the defendant] lived was something
          the agents could have ascertained in many
          other ways. They could have looked him up in
          the telephone book or conducted a computer
          search of drivers' licenses. If they did not
          find him (or if they found too many persons of
          the same name), they could have visited the
          landlord and asked who lived in apartment 1C.

     8 We focus on Concepcion because neither Thompson nor Alvarez
adds anything of relevant substance to Concepcion's analysis.


                              - 24 -
            Instead of asking the landlord who lived
            there, they could have shown the landlord the
            key in their possession and asked the landlord
            to compare it with the key issued to the
            tenant. So too the agents could have followed
            Concepcion around to learn his residence (as
            they did; the key just confirmed what they
            thought they knew).      The information the
            agents obtained from putting the key in the
            lock thus was no secret.

Id. at 1173.   The court contrasted the use of the key to the search

found unreasonable in Hicks.               There, a police officer who was

lawfully present in an apartment to investigate gunfire noticed

expensive    stereo       equipment    including    a    turntable,    moved    the

turntable to record its serial number, and then used the serial

number to determine that the turntable had been stolen.                   See 480

U.S. at 323.         The Supreme Court held that merely moving the

turntable to read its serial number was an unreasonable search,

even though the turntable itself was in plain view, because there

was no probable cause to believe the turntable was stolen.                      See

id.   at   324–26,    326–27.         In   Concepcion,    the   Seventh   Circuit

concluded that trying the key on the lock was a materially more

minimal intrusion than moving the turntable because "[w]hat the

officers learned from inverting the turntable in Hicks they could

not have come by in any other way," while the agents in Concepcion

"invaded    less     of   [the   defendant's]      interest     in   security    of

information when they used the key to verify his address."                      942




                                       - 25 -
F.2d at 1173.      The court thus concluded that neither a warrant nor

probable cause was required to try the key.          Id.

             We question the logic of justifying a search of this

type by reasoning that the information gathered by the search could

have been easily obtained otherwise.         After all, there are likely

many pieces of information within a home that might be obtained

from other sources without searching the home.              It would seem,

too, that the ease of obtaining information elsewhere undercuts

law enforcement's need to access the home more than it necessarily

minimizes    the   nature   of   the   intrusion   into   the   home   or   its

curtilage.

             In any event, the government has made no argument and

offered no evidence that it even considered, much less pursued,

other possible means of determining in which unit Bain resided.

Nor does the government suggest that any exigencies in this case

drove the need to turn the key in the lock of a home.            No claim is

made on appeal that evidence was being destroyed or that an

imminent danger existed that the officers needed to enter unit D

to address.

             One might also say that the officers were merely trying

to identify unit D as Bain's residence, rather than searching

unit D.   Cf. DeBardeleben, 740 F.2d at 445.         Of course, one could

equally say that the officers in Hicks were merely trying to

identify the turntable.          The key point is that the officers


                                   - 26 -
intruded without license or warrant into the curtilage of Bain's

"home" solely to gather information to be used in building a

criminal case against him.     In short, we see no reason to conclude

that the law enforcement-related concerns sufficiently outweighed

the privacy-related concerns to render this search reasonable.9

                                      5.

           Although     we   have     concluded     that    there     was    an

unreasonable search in violation of the Fourth Amendment, that

does not necessarily mean that the evidence seized pursuant to the

warrant   must   be   suppressed.     A    number   of   exceptions   to    the

exclusionary rule exist, and the government has argued two of them:

good-faith reliance on clear precedent and good-faith reliance on

a warrant.10


     9 We do not consider whether the curtilage of unit D extended
to the entire second-floor landing, which might mean that trying
the key on the door to the neighboring apartment was a search of
unit D, or to the entire common space of 131 Laurel Street, which
might mean that trying the key on the door of both of the other
apartments in the building were searches of unit D. As we explain
in footnote 10, infra, we reject on other grounds the independent
source doctrine argument to which these other searches might have
been relevant.
     10At oral argument, the government belatedly sought to argue
that by turning the key in the other two units accessible through
the front entry, the officers generated information from which the
magistrate could infer that the key fit the remaining unit (unit D)
even without taking into account the results of turning the key in
the lock on unit D. See United States v. Dessesaure, 429 F.3d
359, 367 (1st Cir. 2005).      Apart from coming too late, this
argument also fails because the affidavit used to secure the
warrant contained no information from which the magistrate could
determine that only three of the building's four units were
reachable through that entryway.     See Whiteley v. Warden, Wyo.


                                    - 27 -
                                            a.

              The government argues that the officer who turned the

key   relied    in     good   faith    on    precedent     and,    therefore,    the

exclusionary rule should not apply to the information obtained

either from that warrantless search or from the search warrant

obtained      with    affidavits      containing    that    information.        This

argument relies on Davis v. United States, 564 U.S. 229 (2011), in

which   the    Supreme    Court    held      that   evidence      obtained   from   a

warrantless search performed in good-faith reliance on binding

precedent should not be subject to the exclusionary rule.                    See id.

at 235, 240–41.        As applied here, this argument also presumes that

if information obtained in reliance on clear precedent should not

be suppressed, it also should not be excised from a warrant

affidavit in deciding whether there was probable cause to issue

the warrant.         Cf. United States v. Dessesaure, 429 F.3d 359, 367

(1st Cir. 2005).

              The district court accepted these arguments.                   It held

that trying the key on the lock of unit D was a search and a Fourth

Amendment violation, but that the police "reasonably relied" on

this court's earlier opinions in Lyons and Hawkins.                      See Bain,



State Penitentiary, 401 U.S. 560, 565 n.8 (1971) ("Under the cases
of this Court, an otherwise insufficient affidavit cannot be
rehabilitated by testimony concerning information possessed by the
affiant when he sought the warrant but not disclosed to the issuing
magistrate.").


                                       - 28 -
155 F. Supp. 3d at 121–22.        The district court then concluded,

implicitly, that information obtained in good-faith reliance on

precedent need not be excluded from a warrant affidavit when

determining whether the independent source doctrine applies under

Dessesaure.    See id. at 124.

           This court has clarified that "the [Davis] exception is

available only where the police rely on precedent that is 'clear

and well-settled.'"    United States v. Sparks, 711 F.3d 58, 64 (1st

Cir. 2013) (quoting United States v. Davis, 598 F.3d 1259, 1266

(11th Cir. 2010)).    "[T]his emphasis on the clear application of

the precedent to the case at hand is consistent with Davis's focus

on deterrence; where judicial precedent does not clearly authorize

a particular practice, suppression has deterrent value because it

creates   an   'incentive   to   err   on   the   side   of   constitutional

behavior.'"    Id. (quoting Davis, 598 F.3d at 1266-67); see also

United States v. Whitaker, 820 F.3d 849, 854–55 (7th Cir. 2016)

(requiring an on-point holding); United States v. Burston, 806

F.3d 1123, 1129 (8th Cir. 2015) (requiring a holding in a similar

factual context).

           We do not think that Davis covers the police conduct

here.   As discussed above, the facts of Lyons were quite different

from the facts here and were different in ways that a reasonable

person would suspect might be legally significant.            That suspicion

would have been heightened by Jones and Jardines, both of which


                                  - 29 -
were decided before the search in this case occurred in 2014.          In

light of Jardines, it could not have been "clear and well-settled"

that Lyons would apply to testing keys on the locks of houses.

Indeed, Lyons relied on authority that clearly did not apply to

houses in light of Jardines:      Lyons cited Place to support its

conclusion that testing the key on the padlock was not a search.

See Lyons, 898 F.3d at 213 (citing Place, 462 U.S. at 707).        Place

held that using a drug-detecting dog to sniff luggage was not a

Fourth Amendment search.     See 462 U.S. at 707.     Jardines reached

a holding directly to the contrary with respect to houses. Several

of the opinions in Jardines highlighted this distinction.              See

Jardines, 133 S. Ct. at 1419 n.1 (Kagan, J., concurring); id. at

1424 (Alito, J., dissenting).    In light of these distinctions, we

cannot agree that police were acting in accordance with precedent

that was "clear and well-settled."       Sparks, 711 F.3d at 64.11

                                  b.

          The   government   argues    in   the   alternative   that    no

suppression should result because the officers who searched unit D

relied in good faith on the magistrate's issuance of a warrant,



     11This circuit has left open the question as to whether, in
the absence of binding in-circuit precedent, law enforcement may
reasonably rely on out-of-circuit case law as providing
sufficiently clear precedent. See Sparks, 711 F.3d at 63. This
case does not provide an occasion to answer that question because
the government argues only that the officers reasonably relied on
Lyons and Hawkins.


                                - 30 -
even   though   the   affidavit   contains    information   obtained   in

violation of the Fourth Amendment.         In support of this argument,

the government points to United States v. Leon, 468 U.S. 897

(1984).   Under Leon, evidence obtained from a search conducted "in

objectively reasonable reliance on a subsequently invalidated

search warrant" need not always be excluded.           See id. at 922.

Although the existence of a warrant issued by a magistrate will

usually establish this form of good faith, "in some circumstances

the officer will have no reasonable grounds for believing that the

warrant was properly issued."       Id. at 922–23 (footnote omitted).

The Leon court provided examples of four such circumstances:

(1) "if the magistrate or judge in issuing a warrant was misled by

information in an affidavit that the affiant knew was false or

would have known was false except for his reckless disregard of

the truth," id. at 923 (citing Franks v. Delaware, 438 U.S. 154

(1978)); (2) "where the issuing magistrate wholly abandoned his

judicial role," id.; (3) when an affidavit is "so lacking in

indicia of probable cause as to render official belief in its

existence entirely unreasonable," id. (quoting Brown v. Illinois,

422 U.S. 590, 610–611 (1975) (Powell, J., concurring in part));

and (4) when, "depending on the circumstances of the particular

case, a warrant [is] so facially deficient--i.e., in failing to

particularize the place to be searched or the things to be seized-

-that the executing officers cannot reasonably presume it to be


                                  - 31 -
valid." Id. We review the application of the good-faith exception

de novo.     See United States v. Baez, 744 F.3d 30, 33 (1st Cir.

2014).

             Here, we have a circumstance not expressly addressed in

Leon:     the warrant affidavit forthrightly discloses facts that

establish probable cause, but one of the facts essential to

establishing probable cause (the result of the key turn) was

obtained as a result of an unconstitutional search. We encountered

a very similar circumstance in United States v. Diehl, 276 F.3d 32

(1st Cir. 2002).       In Diehl, the defendant sought suppression of

evidence "seized pursuant to a facially valid warrant."                  Id. at

34.     As in this case, the warrant affidavit contained a report

that an officer had previously approached the searched location

and this report "was necessary to establish the probable cause

justifying     issuance   of   the    warrant."      Id.     at    35,   41–42.

Anticipating Jardines, this court concluded that the officer's

earlier visit to the location was an unconstitutional search

because it involved a warrantless trespass on the curtilage of the

residence.     See id. at 38, 41.       Nevertheless, we concluded that

Leon's good faith exception applied.          In so ruling, we focused on

the   accuracy   and    completeness     of   the   manner    in    which   the

information supporting the warrant was conveyed to the magistrate

issuing the warrant.      Placing the burden on the government, id. at

42, we asked whether the affiant's recitation of the facts was


                                     - 32 -
infected "with an intentional misrepresentation, or one made with

reckless disregard of the truth," so as to mislead the magistrate.

Id.      We   asked   as   well   whether,   by   omission   or   error,   the

description "[took] away from the issuing court the ability to

decide" the curtilage issue for itself.            Id. at 42-43.     We also

asked whether enough information was given to the issuing judge to

determine whether the officer who invaded the curtilage acted "in

such bad faith as to preclude a warrant."          Id. at 43.     Finally, we

noted the possibility that snow cover may have misled the officers

as to the contours of the curtilage, which would further negate

any inference of bad faith.          Id.     All in, we found the case to

present "'a penumbral zone' within which an inadvertent mistake

would not call for exclusion." Id. (quoting Leon, 468 U.S. at 925

n.26).

              Diehl's application of the Leon good-faith exception

finds company in the majority of circuits that have considered the

question posed by reliance on a warrant that is itself tainted by

the results of an unconstitutional search.             See, e.g., Hopkins,

824 F.3d at 733; United States v. Ganias, 824 F.3d 199, 222–23 (2d

Cir. 2016) (en banc); United States v. Massi, 761 F.3d 512, 528

(5th Cir. 2014); United States v. McClain, 444 F.3d 556, 565–66

(6th Cir. 2005).       At least two circuits have disagreed with this

majority view, see, e.g., United States v. McGough, 412 F.3d 1232,

1239–40 (11th Cir. 2005); United States v. Wanless, 882 F.2d 1459,


                                    - 33 -
1466–67 (9th Cir. 1989), as have a few commentators, see, e.g.,

1 Wayne R. LaFave, Search & Seizure:     A Treatise on the Fourth

Amendment § 1.3(f) (5th ed. 2016) (stating that "there is good

reason to doubt" whether the plurality rule is correct); Craig M.

Bradley, The "Good Faith Exception" Cases:   Reasonable Exercise in

Futility, 60 Ind. L.J. 287, 302 (1985) ("When the magistrate issued

the warrant, he did not endorse past activity; he only authorized

future activity . . . .     [T]he function of the magistrate is to

determine 'whether a particular affidavit establishes probable

cause,' not whether the methods used to obtain the information in

that affidavit were legal." (quoting Leon, 468 U.S. at 914)).

Diehl would seem to suggest that the minority position takes too

cramped a view of what magistrates do, and accords too much

relevance to a distinction that may have no bearing on the presence

or absence of good faith.    Diehl, 276 F.3d at 42-43.   Be that as

it may, this case presents no reason to deviate from Diehl's

interpretation of Leon.     Under Diehl, good faith reliance on a

warrant procured and issued in good faith saves the fruits of a

warranted search from suppression.

           So, we turn to the question of good faith.    Unlike in

Diehl, the invasion of the curtilage in this case could not be

said to be the result of the officer's misapprehension of the

facts.   Here, any misapprehension was purely a misapprehension of

the law.   Diehl offers no direct guidance on how to define the


                               - 34 -
point at which such a misapprehension equates with the bad faith

that would negate reliance on the warrant.     Pointing to United

States v. Hopkins, 824 F.3d 726 (8th Cir.), cert. denied, 137 S.

Ct. 522 (2016), the government says that we should find the Leon

good faith exception applicable because the key-turn was "close

enough to the line of validity to make the officers' belief in the

validity of the warrant objectively reasonable." Id. at 733. Bain

declines to argue that we should not employ Hopkins's formulation.

Rather, he argues that the officers' conduct here fails to qualify

under    that   formulation.     Hopkins's   focus   on   objective

reasonableness seems to align with Leon's repeated references to

reasonableness.    This alignment, coupled with Bain's failure to

contest the application of Hopkins, leads us to employ Hopkins's

formulation, albeit by assuming rather than deciding that such a

formulation is the proper one for measuring the officer's good

faith.

           Applying this formulation, we conclude that the police

could rely in good faith on the search warrant in this case.    As

we have explained, our decisions in Lyons and Hawkins did not

clearly classify the turning of a key in an apartment lock as being

a reasonable search.   Warrants, though, make a difference.    Once

the magistrate issued a warrant, the relevant question was no

longer whether clear precedent blessed the search upon which the

warrant was based in part.     Rather, the question became whether


                               - 35 -
precedent pointed enough in that direction to allow an objectively

reasonable     officer   informed   about   the   law   to   conclude

(erroneously, as we have now explained) that he could turn a key

in the lock of unit D on the basis of a reasonable suspicion short

of probable cause.

             We think that reasonable officers informed about the law

(prior to the issuance of this opinion) could have so concluded.

Indeed, the Massachusetts Supreme Judicial Court had so concluded,

holding that only reasonable suspicion was required for just such

a search.     See Alvarez, 661 N.E.2d at 1302.    So, too, as we have

noted, did the Seventh Circuit in Concepcion, and it did so on

grounds not directly rejected in Jardines.        See Concepcion, 942

F.2d at 1172–73.      Given the facts known to the officers at the

time they tried the keys, it was reasonable to suspect that turning

the key on the lock to unit D would lead to evidence of Bain's

drug dealing.    There was good reason to believe Bain was residing,

at least temporarily, in one of the apartments accessible through

the front door of 131 Laurel Street:        He had been seen there

previously both during the day and late at night, and he walked

out that front door right before his arrest.       His keys, in turn,

did not work in the doors of two other units, leaving a fifty

percent chance that they would fit unit D.12       As we will discuss


     12In fact, only three units were accessible through the front
door, but this fact, although helpful to establishing probable


                                - 36 -
in the next section, there was a nexus between Bain's drug dealing

and the location where he was residing.        Given the presence of

reasonable suspicion, and given the state of the law prior to

today's decision holding the key turning to constitute an unlawful

search, checking the keys on the door to unit D was sufficiently

close to the line of validity that the police could rely in good

faith on the search warrant.

                                 c.

          Finally,   Bain   raises    an   alternative   argument   for

suppressing the fruits of the warranted search.      He contends that

the warrant was defective because the affidavits provided no

probable cause to believe that evidence of his suspected crime

would be found in unit D, even without excising the fact that a

key in his possession opened unit D.       The question posed by this

argument is whether the warrant affidavits were "so lacking in

indicia of probable cause as to render official belief in its

existence entirely unreasonable."     Leon, 468 U.S. at 923.

          Bain does not challenge that the police had probable

cause to believe that he committed a crime; instead, he argues

that the search warrant affidavits did not establish an adequate

nexus between that crime and unit D.        "When it comes to nexus,


cause, was not clearly set forth in the affidavits used to secure
the search warrant. Whether we could rely on such an undisclosed
but favorable fact given the absence of any motive to conceal it,
we need not decide.


                               - 37 -
common sense says that a connection with the search site can be

deduced 'from the type of crime, the nature of the items sought,'

plus 'normal inferences as to where a criminal would hide' evidence

of his crime."    United States v. Rivera, 825 F.3d 59, 63 (1st Cir.

2016) (quoting United States v. Feliz, 182 F.3d 82, 88 (1st Cir.

1999)).      This court has, "with a regularity bordering on the

echolalic, endorsed the concept that a law enforcement officer's

training and experience may yield insights that support a probable

cause determination."     United States v. Floyd, 740 F.3d 22, 35

(1st Cir. 2014).    We also have a line of precedent that addresses

when police have probable cause to search the homes of people known

to be selling drugs.    See United States v. Barnes, 492 F.3d 33, 37

(1st Cir. 2007); United States v. Ribeiro, 397 F.3d 43, 49 (1st

Cir. 2005); Feliz, 182 F.3d at 87–88. We have expressed skepticism

that probable cause can be established by the combination of the

fact that a defendant sells drugs and general information from

police officers that drug dealers tend to store evidence in their

homes.    See Ribeiro, 397 F.3d at 50-51 (citing United States v.

Schultz, 14 F.3d 1093, 1097 (6th Cir. 1994)); Feliz, 182 F.3d at

87–88.    However, the addition of specific facts connecting the

drug dealing to the home can establish a nexus.     See Ribeiro, 397

F.3d at 51.

             The warrant affidavits established that Bain had access

to unit D.    True, they did so by relying on the unlawfully obtained


                                - 38 -
information establishing that the key fit the lock on unit D.              But

as we have already explained, that defect did not undermine the

officers' ability to rely on the warrant.            So, the only question

was whether Bain was staying there in the sense that one would

expect to find his possessions there.             We think the affidavits

create a fairly strong inference that he was.            Officer Connerney

stated that when Bain lived with his brother in Waltham, Connerney

regularly observed Bain's car parked outside.                 After Bain was

arrested for assaulting his brother, he told his probation officer

that   he   would   live   at   his    mother's   residence    in   Arlington.

Connerney stated that he had never seen Bain at that residence and

had never seen Bain's car parked outside that residence. Connerney

also stated that since the controlled purchase on March 21,

officers had seen Bain's car parked on Webster Street in Malden,

near 131 Laurel Street, on several occasions.             On two of those

occasions, March 28 and 29, officers could have reasonably inferred

that Bain stayed in the area overnight.

            Bain also argues that even if there was probable cause

to believe he was living in unit D, the affidavits do not establish

probable cause to believe that evidence of his heroin dealing would

be found there.     The affidavits raise the inference, though, that

Bain's practice was to deliver the product near a location where

he resided, first near his brother's apartment in Waltham, and

then near 131 Laurel Street after he moved.             And at the moment


                                      - 39 -
that he was arrested exiting the home, he was apparently carrying

(or a reasonable officer could infer he was carrying) a relatively

small amount of heroin.   Neither his person nor his car contained

any of the items that a repeat drug seller very often has (a source

stash, cash, and records).13   Neither his altercation-induced exit

from his brother's apartment nor any other information in the

warrant affidavits even hinted at any other location that might

contain the expected accoutrements of an experienced dealer.   All

in all, and whether or not this added up to probable cause of a

nexus to unit D, it was enough so that we cannot say that the

nexus-related evidence upon which the warrant rested was "so

lacking in indicia of probable cause as to render official belief

in its existence entirely unreasonable."   Leon, 468 U.S. at 923.

                                  d.

          Finally, we consider whether the district court erred in

failing to suppress testimony at trial from two police officers

describing how they used Bain's keys to open the door to unit D

immediately after his arrest.    We have concluded that the police

could not have relied in good faith on precedent to conduct this

warrantless search in the first instance, but that they could rely

in good faith on the warrant when conducting the later warranted



     13 Although the affidavits do not make this negative claim,
we may infer it from the affidavits' failure to report finding any
evidence of this sort on Bain or in his car.


                                - 40 -
search.   In short, the direct results of the warrantless key-turn

search were inadmissible, but that infirmity did not taint the

results of the subsequent warranted search.     These conclusions

have the following consequence:   Unless the warranted search also

revealed that the keys in Bain's possession at the time of his

arrest fit the lock on the door to unit D, it was error to admit

this testimony.

           The government has not pointed us to any testimony

establishing that the police retested the keys on the lock after

the warrant issued.    We have not found any.14    Therefore, the

district court should have suppressed the officers' testimony

about using Bain's keys to open the door to unit D immediately

after his arrest.

           Nevertheless, we conclude that admitting this testimony

was harmless beyond a reasonable doubt. See United States v. Rose,

802 F.3d 114, 124 (1st Cir. 2015) (affirming denial of motion to

suppress because, even if defendant were correct that evidence

should have been suppressed because there was no independent

source, the "government [could] prove beyond a reasonable doubt

that the [putative] error complained of did not contribute to the

verdict obtained." (second alteration in original) (quoting United


     14Since the apartment was leased to a person other than Bain,
and since officers remained at 131 Laurel Street while Connerney
sought the warrant, we cannot presume that anyone must have used
the keys to re-enter unit D.


                              - 41 -
States v. Green, 698 F.3d 48, 53–54 (1st Cir. 2012))).         As in Rose,

although    the   government   referred   to    the   improperly   obtained

evidence in both its opening and closing arguments, "the remaining

evidence was so overwhelming that, even if this evidence should

have been excluded, its inclusion did not affect the verdicts."

Id.   As we have summarized above, the warranted search uncovered

overwhelming evidence that Bain resided, at least temporarily, in

unit D.    His government-issued identification cards were in one of

the closets, along with a health insurance card, auto insurance

card, and AAA card, all in his name.           The other closet contained

a large quantity of men's clothing and shoes in Bain's size,

including a sneaker containing $20 bills that the cooperating

witness had used to purchase heroin from Bain.           A parking ticket

for Bain's car was found on a chair.           We have no doubt that the

jury would have concluded that Bain possessed the drugs and gun in

unit D even if the court had excluded the testimony about his keys.

                                   II.

            Bain argues that even if the suppression motion properly

failed, the district court still should not have admitted at trial

evidence that there was a credit-card-making machine in one of the

closets of unit D.       We review the judge's evidentiary ruling

admitting this evidence for abuse of discretion. See United States

v. Gemma, 818 F.3d 23, 35 (1st Cir. 2016); United States v.

Varoudakis, 233 F.3d 113, 118 (1st Cir. 2000).


                                 - 42 -
          As described in section I.A, supra, in the closet of one

of the bedrooms in unit D, police found a credit-card-making

machine inside an opaque trash bag along with boxes of blank cards.

A government witness testified that when Bain was arrested, the

police found four credit cards on his person.      Another witness

testified that those credit cards were fake and that the machine

found in the closet could have been used to make them.      In the

same closet as the credit-card-making machine, police found men's

sneakers, which contained around $7,000 in cash.   Five of the $20

bills in the shoes were government funds that the cooperating

witness had used in the March 21 controlled buy.

          Bain challenged the admission of the credit-card-making

machine in a motion in limine.   The district court concluded that

"[t]he Government may present evidence regarding the credit card

making equipment for the purpose of connecting Defendant to the

apartment in question and establishing that Defendant had control

over the area in which the items were found." At trial the district

court gave two limiting instructions on this evidence.   The first

was that the jury should not use the evidence to decide whether

"other wrongful acts did or did not occur."    The second was that

the jury should not "consider the evidence as proof that the

Defendant [ha]s a bad character or any propensity to commit crime."

          A proposal by the government to introduce evidence of a

defendant's other bad acts is subject to a two-part test.      See


                              - 43 -
United States v. Hicks, 575 F.3d 130, 142 (1st Cir. 2009). "First,

a court must ask whether the proffered evidence has a 'special'

relevance,    i.e.,    a    non-propensity     relevance."          Id.     Under

Rule 404(b), "[e]vidence of a crime . . . is not admissible to

prove a person's character in order to show that on a particular

occasion the person acted in accordance with the character."                 Fed.

R. Evid. 404(b)(1).         But such evidence "may be admissible for

another purpose, such as proving motive, opportunity, intent,

preparation, plan, knowledge, identity, absence of mistake, or

lack of accident."         Fed. R. Evid. 404(b)(2).       If other bad acts

evidence has special relevance under Rule 404(b), the court must

consider whether the evidence should nevertheless be excluded

under Rule 403.       See Hicks, 575 F.3d at 142.             "The court may

exclude relevant evidence if its probative value is substantially

outweighed by a danger of . . . unfair prejudice."                        Fed. R.

Evid. 403.

             Bain   first   argues   that     the   machine   had    no   special

relevance under Rule 404(b).         Conceding that "evidence tending to

tie an individual to a certain location might, in some instances,

have special relevance," he argues, first, that the testimony about

the capabilities of the machine did not match up with the nature

of the fake cards in his pocket.         He also argues that the machine

did not connect him to unit D because there was no evidence that




                                     - 44 -
the cards in his pocket were uniquely connected to the machine,

that he had made the cards himself, or that he knew they were fake.

            Bain's first argument relies on a factual predicate that

one of the government's witnesses contradicted.                A secret service

agent called by the government testified that the machine could

have been used to make the fake credit cards in Bain's pocket.

Bain argues, essentially, that this testimony was contradicted by

the   witness's     prior   statement    that    the    machine    was   a   "card

embosser" combined with the (claimed) fact that the cards were not

actually embossed.      As is often the case, this type of argument,

which highlights a contradiction in a witness's testimony and

insists that one statement should be believed over another, is an

argument about probative value.          A jury could believe the agent's

statement that the machine could make the unembossed cards in

Bain's pocket notwithstanding the agent's reference to the machine

as a card embosser.15

            Bain's latter arguments also attack probative value

rather than special relevance.             See, e.g., United States v.

Gentles, 619 F.3d 75, 87 (1st Cir. 2010).                   The presence of the

machine in the unit and the fake credit cards in Bain's pocket,

combined with the testimony that the machine could make those

cards, made it more likely that he had been in the unit, that he


      15   Bain's   trial   counsel    chose    not    to    cross-examine    this
witness.


                                      - 45 -
stored his possessions in the unit, that he stored his possessions

in that closet in particular, and thus that he controlled other

items in that closet, including the sneaker with the money in it.

This chain of inferences establishes special relevance.         See Fed.

R. Evid. 401 (defining "relevant" evidence); United States v. Doe,

741 F.3d 217, 229 (1st Cir. 2013) (stating that evidence has

special relevance if "it is relevant for any purpose apart from

showing propensity to commit a crime").        The existence of other

possible chains of inference does not undermine special relevance;

it goes to probative weight.

            Bain next argues that the machine's probative value was

substantially outweighed by the risk of unfair prejudice, so it

should have been excluded under Rule 403.           He posits that the

probative   value   of   the   credit-card-making   machine   was   slight

because it was cumulative of other evidence showing that he lived

at the unit (e.g., observations of him leaving the building, the

presence of his identification cards in the unit, the presence of

money used in one of the controlled buys in the unit).        This small

probative value, he argues, was substantially outweighed by a risk

the jury would infer he was engaged in credit-card fraud and,

therefore, had a bad character.

            When assessing the probative value of evidence under

Rule 403, a court must consider both whether the evidence was

offered to prove an issue that was in genuine dispute, and whether


                                  - 46 -
the evidentiary point could have been made with other evidence

that did not present a risk of unfair prejudice. See United States

v. Ford, 839 F.3d 94, 109–10 (1st Cir. 2016); Varoudakis, 233 F.3d

at 122.    The risk of prejudice from admitting a piece of evidence

may be "cabined" by a limiting instruction.        See United States v.

Pelletier, 666 F.3d 1, 6 (1st Cir. 2011).

            The Rule 403 issue is a close one.           Bain's defense at

trial was that:    (1) the recordings of the controlled buys did not

establish definitively that he sold drugs to the cooperating

witness; (2) the cooperating witness was unreliable; and (3) the

items in the unit were not his.      He advanced these defenses both

in opening and in closing.        The government did have abundant

evidence    that   Bain   was   connected     to   the    unit,   and   the

identification cards were far more probative of Bain's control

over the drugs, gun, and ammunition found in one of the closets

than the credit-card-making machine.        But Bain also denied that he

had engaged in the controlled buys, making it crucial to the

government's case to establish his control over the money in the

sneaker in the closet of the other bedroom.              The credit-card-

making machine was probative on that point.              In light of this

probative value, the issues disputed at trial, and the limiting

instructions, we cannot conclude that the district court abused

its discretion in admitting the credit-card-making machine.             See

United States v. Smith, 292 F.3d 90, 99, 100–01 (1st Cir. 2002)


                                 - 47 -
(noting that "[w]e usually defer to the district court's balancing

under Rule 403 of probative value against unfair prejudice" and

factoring   the   district   court's   limiting   instruction   into   the

Rule 403 analysis).

                                  III.

            Finally, we consider the sentencing issue.      Bain argues

that he did not have three prior convictions for "serious drug

offenses," and therefore did not qualify for the ACCA's fifteen-

year mandatory minimum sentence.16         He did not preserve this

argument below, so we review only for plain error.17

            The ACCA provides:

            In the case of a person who violates
            section 922(g) of this title and has three
            previous convictions by any court . . .
            for . . . a serious drug offense . . .
            committed on occasions different from one
            another, such person shall be . . . imprisoned
            not less than fifteen years . . . .

18 U.S.C. § 924(e)(1).       A "serious drug offense" under the ACCA

includes, in relevant part,



     16 He also argues that the fact of a prior conviction must be
found by a jury beyond a reasonable doubt. He acknowledges that
we are bound by precedent to reject this argument, see Almendarez-
Torres v. United States, 523 U.S. 224, 226–27 (1998), and raises
it only to preserve it for further review.
     17The government argues that Bain waived--and did not merely
forfeit--his argument that he should not have been subject to the
ACCA mandatory minimum. We do not decide this question because we
assume, favorably to the defendant, that the plain error standard
applies.


                                 - 48 -
          an   offense  under  State  law,  involving
          manufacturing, distributing, or possessing
          with intent to manufacture or distribute, a
          controlled substance (as defined in section
          102 of the Controlled Substances Act (21
          U.S.C. 802)), for which a maximum term of
          imprisonment of ten years or more is
          prescribed by law[.]

Id. § 924(e)(2)(A)(ii).

          The probation officer who prepared Bain's Presentence

Investigation Report (PSR) concluded that Bain had three prior

convictions for serious drug offenses:     a 2002 conviction for

possession of cocaine with intent to distribute, a 2006 conviction

for possession of crack cocaine with intent to distribute, and a

2006 conviction for trafficking twenty-eight to one hundred grams

of cocaine, all under Massachusetts law.   Bain did not object to

this conclusion, and the district court accepted it.   On appeal,

Bain belatedly argues that his 2006 Massachusetts conviction for

trafficking cocaine, see Mass. Gen. Laws ch. 94C, § 32E(b), does

not fall under the definition of a "serious drug offense."

          Determining whether Bain's prior conviction falls into

this definition requires looking at the Massachusetts statute

under which he was convicted and the relevant state precedent.

The statute reads:

          Any person who trafficks in a controlled
          substance [as defined to include cocaine] by
          knowingly or intentionally manufacturing,
          distributing or dispensing or possessing with
          intent to manufacture, distribute or dispense
          or by bringing into the commonwealth a net


                             - 49 -
            weight of 18 grams or more of a controlled
            substance as so defined, or a net weight of 18
            grams or more of any mixture containing a
            controlled substance as so defined shall [be
            punished by a term of imprisonment that varies
            depending on weight].

Id.    The parties' dispute focuses on the form of trafficking

committed by "bringing into the commonwealth a net weight of 18

grams or more of [cocaine], or a net weight of 18 grams or more of

any mixture containing [cocaine]."      Id.   Bain argues that this

form of the offense is not a serious drug offense.      He does not

dispute that the other forms of trafficking are serious drug

offenses.

            We need not and do not determine whether Bain is right

that the "bringing into the commonwealth" form of the offense is

not a serious drug offense.    Instead, we assume that he is right18

but conclude that he still cannot satisfy the plain error standard

because he cannot establish that the Massachusetts trafficking

statute is clearly "indivisible." We pause for a moment to explain

what that means.

            When determining whether a prior conviction qualifies as

a predicate offense under the ACCA, we do not look at the specific

facts of the defendant's prior conviction.       Instead, we use a

categorical approach, where we classify crimes as ACCA predicates


      18There is a strong reason to think he is indeed correct
under our precedent. See United States v. Mulkern, 854 F.3d 87,
96–97 (1st Cir. 2017).


                               - 50 -
based on their legal definitions, rather than the facts of the

defendant's particular conviction.          See Mathis v. United States,

136 S. Ct. 2243, 2248, 2251–52 (2016); Descamps v. United States,

133 S. Ct. 2276, 2283 (2013).      The categorical approach is imposed

in part by the language of the ACCA, see Johnson v. United States,

135 S. Ct. 2551, 2562 (2015); Shepard v. United States, 544 U.S.

13, 19 (2005); Taylor v. United States, 495 U.S. 575, 600 (1990),

and in part by the Sixth Amendment concerns that would arise if

the imposition of the ACCA's mandatory minimum sentence were based

on the actual facts underlying prior convictions as found by the

sentencing judge, see Shepard, 544 U.S. at 24; Taylor, 495 U.S. at

601; United States v. Faust, 853 F.3d 39, 50 (1st Cir. 2017)

(citing Mathis, 136 S. Ct. at 2252, and Descamps, 133 S. Ct. at

2288).

           The categorical approach proceeds in different ways for

different portions of the ACCA.      To determine whether a conviction

for a crime falls within the "force clause" or the "enumerated

offense clause" of the violent felony definition, see United States

v. Starks, 861 F.3d 306, 314 (1st Cir. 2017) (defining these

terms),   courts   ask   whether   there    is   any   (realistic)   way   of

committing the crime that does not satisfy the force clause or the

elements of the generic version of the enumerated offense.             See,

e.g., Mathis, 136 S. Ct. at 2248 (enumerated offense clause);

Faust, 853 F.3d at 51 (force clause).             To determine whether a


                                   - 51 -
conviction for a crime falls within the now-invalidated "residual

clause" of the violent felony definition, see Starks, 861 F.3d at

314, courts asked whether the "ordinary case" of a conviction for

that crime created a risk of physical injury that exceeded a

difficult-to-specify threshold.           See, e.g., Johnson, 135 S. Ct. at

2557–59.

           In    this       circuit,   when     analyzing   whether   a   prior

conviction is a serious drug offense, we have followed the approach

used with the force clause and the enumerated offenses clause and

asked whether (as determined from the crime's definition and state

cases implementing that definition) every realistically possible

way of committing the offense satisfies the definition of a serious

drug offense.        See United States v. Mulkern, 854 F.3d 87, 96–97

(1st Cir. 2017); United States v. Whindleton, 797 F.3d 105, 109

(1st Cir. 2015) ("Since Whindleton's record of conviction does not

specify on what theory he was convicted, we must ensure that any

form of the conviction would qualify as a 'serious drug offense'

under the ACCA."), cert. dismissed, 137 S. Ct. 23, cert. denied,

137 S. Ct. 179 (2016).         This approach makes good sense, given that

the difficulties involved in applying the ordinary case approach

contributed     to    the    conclusion   that    the   residual   clause   was

unconstitutionally vague.         See Johnson, 135 S. Ct. at 2557–58.

           Not all criminal statutes define only a single crime.

"Some statutes . . . have a more complicated (sometimes called


                                       - 52 -
'divisible') structure . . . .              A single statute may list elements

in the alternative, and thereby define multiple crimes."                       Mathis,

136 S. Ct. at 2249.                "A sentencing court thus requires a way of

figuring out which of the alternative elements listed . . . was

integral to the defendant's conviction . . . ."                    Id.    "To address

that need, th[e Supreme] Court approved the 'modified categorical

approach'    for       use     with    statutes    having    multiple     alternative

elements."       Id.    "Under that approach, a sentencing court looks to

a limited class of documents (for example, the indictment, jury

instructions, or plea agreement and colloquy) to determine what

crime, with what elements, a defendant was convicted of."                          Id.

(citing, inter alia, Shepard, 544 U.S. at 26).                           We call this

limited class of documents "Shepard documents."

            Not        all    crimes    that     can   be   committed     in   multiple

different ways are divisible into multiple crimes with different

elements.        There is "a different kind of alternatively phrased

law:    not one that lists multiple elements disjunctively, but

instead one that enumerates various factual means of committing a

single element."             Id.    In order to determine whether a crime that

may be committed in multiple different ways is divisible, we must

be   able   to    distinguish          between    crimes    that   have   alternative

elements and crimes that have a single set of elements that may be

satisfied by different means.                  There are a number of different

ways of distinguishing elements from means, including looking at


                                          - 53 -
jury unanimity requirements, relevant model jury instructions,

certain statutory provisions, and indictments.       See Starks, 861

F.3d at 316.

             Finally, "if state law fails to provide clear answers"

about what are elements and are means, "federal judges have another

place to look:    the record of a prior conviction itself," Mathis,

136 S. Ct. at 2256, that is, the Shepard documents.       If neither

state law nor the Shepard documents "speak[s] plainly" about

whether a crime is divisible, a sentencing court must assume that

it is not.    See id. at 2257.

             This case involves another layer of complexity:     the

plain error standard.     Generally, it is the government's burden to

prove that a defendant has three predicate convictions under the

ACCA.   See Mulkern, 854 F.3d at 90.        Thus, when a statute is

divisible and some forms of the offense are ACCA predicates and

some forms are not, the government bears the burden of proving

that the defendant was convicted of a form that is an ACCA

predicate.    See id.   But that burden shifts on plain error review.

When a defendant fails to preserve an objection to the government's

contention that a prior conviction for a divisible offense was for

the qualifying form of that offense, the defendant can only win on

appeal by proving that the conviction was not for the qualifying

form of the offense. See United States v. Serrano-Mercado, 784




                                 - 54 -
F.3d 838, 846–49 (1st Cir. 2015), cert. denied, 137 S. Ct. 812

(2017).19

            This case presents a related issue of first impression:

What do we do on plain error review when state law lacks clarity

on the question of divisibility and the record lacks the Shepard

documents to which we might otherwise refer in an attempt to

resolve that ambiguity?      Under Mathis, when state law is unclear

about the elements of a crime, a sentencing court may consult the

Shepard documents to determine whether the crime is divisible.

Normally, the government must introduce these documents and prove

that the crime is divisible in order to carry its burden of proving

that the defendant was convicted of a form of an offense that

qualifies as an ACCA predicate.       See United States v. Dávila-

Félix, 667 F.3d 47, 55 (1st Cir. 2011).    But in this case, like in

Serrano-Mercado, the government did not introduce any Shepard

documents    because   the    defendant   did   not   challenge   his

classification as an armed career criminal.       Thus, there are no

Shepard documents in the record on appeal.      See Serrano-Mercado,

784 F.3d at 847–48.     If we conclude that Massachusetts law is

unclear as to whether trafficking is divisible, we will have no

way of resolving the divisibility inquiry.      Cf. id.




     19This rule is subject to an exception not applicable here.
See Serrano-Mercado, 784 F.3d at 849.


                                 - 55 -
             We conclude that the Serrano-Mercado rule extends to

these circumstances.       On plain error review, a defendant arguing

that a prior conviction was improperly counted as an ACCA predicate

because there is a non-qualifying form of the offense bears the

burden of proving either (1) that the offense is indivisible; or

(if the offense is not shown to be indivisible) (2) that the prior

conviction was for the non-qualifying form of the offense.           Thus,

such a defendant can only win on plain error review in the absence

of Shepard documents if the prior conviction was for a crime that

has a non-qualifying form and its indivisibility can be clearly

ascertained without any need to look at Shepherd documents as

Mathis allowed.20

             We reach this conclusion because abandoning the Serrano-

Mercado    rule    in   these   circumstances   would   produce   anomalous

results.     Imagine two defendants, both of whom fail to object to

their classification as armed career criminals and both of whom

have at least one predicate offense with a non-qualifying form.

Neither introduces any Shepard documents at sentencing.                Both

appeal their sentences.         By the vagaries of state law, it turns

out   that   one   defendant's    questionable   predicate   offense   was

clearly divisible under state law at the time of the conviction,

while the other defendant's questionable predicate offense was not


      20This burden-shifting rule retains the exception for the
circumstances outlined in Serrano-Mercado. See 784 F.3d at 849.


                                    - 56 -
clearly divisible under state law at the time of the conviction.

Serrano-Mercado requires that the former bear the burden of proving

that    his    conviction   was    for    the   non-qualifying    form   of   the

divisible offense using Shepard documents.                 We think the latter

should be likewise required to prove that the offense was not

divisible at the time of the prior conviction, also using Shepard

documents, under the procedure contemplated in Mathis.               We decline

to create such an arbitrary distinction.

              Having reached this conclusion, Bain's appeal can only

succeed       on   the   plain    error   standard    if    the   Massachusetts

trafficking statute was clearly indivisible at the time of his

conviction.        But we conclude that, based on the arguments made to

us in this appeal, the statute's divisibility is unclear.21

              Bain's argument that the statute was clearly indivisible

rests on several Massachusetts cases, which, he argues, establish

that a jury need not be unanimous about the type of trafficking

for which a defendant has been convicted.              We do not read these

cases to establish any clear rule that bears on the statute's

divisibility.

              The Massachusetts Supreme Judicial Court has not clearly

held whether the different ways of committing the trafficking

offense are different crimes with different elements or simply


       21
        Neither the defendant nor the government has pointed us
toward any model jury instructions for this statute.


                                      - 57 -
different means of committing a single crime.                  It has described

the statute as "disjunctive, setting forth three categories of

trafficking:     (1)      manufacturing,       distributing,      or    dispensing

fourteen grams or more of cocaine; (2) possessing with intent to

manufacture, distribute, or dispense fourteen grams or more; and

(3)   bringing   into     the     Commonwealth     fourteen    grams    or   more."

Commonwealth v. Roman, 609 N.E.2d 1217, 1218 (Mass. 1993); see

also Commonwealth v. Chappee, 492 N.E.2d 719, 727 (Mass. 1986).

It has not, however, clarified whether this disjunctive form bears

on the elements of the offense.

            There is some suggestion in Roman that an indictment

need only allege "trafficking," without specifying the form of

trafficking.     There, the SJC reviewed whether there was sufficient

evidence   before      the    grand   jury    to   indict   the   defendant     for

trafficking.        Id.      at   1218.      It    concluded   that     there    was

insufficient evidence for trafficking on an importation theory,

but sufficient evidence on a possession with intent to distribute

theory.    Id. at 1219.       The opinion does not quote the indictment,

however, so this hardly constitutes a clear holding.

            The Massachusetts Appeals Court has also issued several

opinions that are ambiguous as to the elements of the offense.

Like Roman, one opinion suggests that the statute merely creates

one   crime--"trafficking"--that             can   be   committed      in    several

different ways.        See Commonwealth v. Silva, 488 N.E.2d 34, 37


                                      - 58 -
(Mass. App. Ct. 1986).      But the court's only holding in Silva was

that the three ways of committing the first type of trafficking--

"manufacturing,       distributing,   or   dispensing"--are,   in   fact,

disjunctive.    Id.    That holding does not help Bain.

           Bain also points to several cases holding that evidence

adduced at trial or facts admitted in connection with a guilty

plea were sufficient to support a conviction for trafficking under

multiple theories. See Commonwealth v. Rodriguez, 855 N.E.2d 1113,

1123 (Mass. App. Ct. 2006) (sufficient evidence at trial), aff'd

877 N.E.2d 1274 (Mass. 2007); Commonwealth v. Panopoulos, No. 99-

P-2023, 2001 WL 695106, at *1 (Mass. App. Ct. June 20, 2001)

(unpublished disposition) (guilty plea); Commonwealth v. Manrique,

581 N.E.2d 1036, 1040 (Mass. App. Ct. 1991) (sufficient evidence

at trial).     None of these cases demonstrate that the statute was

clearly indivisible.       In Rodriguez, "[t]he judge instructed the

jury on two theories of cocaine trafficking:        possession with the

intent to distribute, and 'bringing into' the Commonwealth."         855

N.E.2d at 1123 (quoting Mass. Gen. Laws ch. 94C, § 32E(b)(4)).

"The judge also told the jurors that they had to be unanimous as

to either or both theories, but there was no special verdict form."

Id.   The court concluded that there was, nevertheless, no error in

submitting a general verdict form to the jury because "the evidence

[was] sufficient to sustain a guilty verdict under both theories."

Id. at 1124.    Rodriguez points in both directions on divisibility.


                                  - 59 -
The trial judge's instruction that the jury had to be unanimous as

to its theory of the case supports the conclusion that the offense

was divisible.   Nothing in the court's decision suggests that this

instruction was incorrect or that the use of a general verdict

form obviated this instruction under state law.     The conclusion

that there was no error in submitting a general verdict form given

that the evidence was sufficient to convict on either theory may

cut the other way, but it may also simply be an application of a

Massachusetts rule that a general verdict of guilty will stand if

there is sufficient evidence for all the theories put before the

jury.    See, e.g., Commonwealth v. Oquendo, 982 N.E.2d 538, 542

(Mass. App. Ct. 2013) (citing Commonwealth v. Plunkett, 664 N.E.2d

833, 836 (Mass. 1996)).      Rodriguez is simply ambiguous on this

point.   Manrique and Panopoulos were just sufficiency challenges,

not challenges to a verdict form, and are to the same effect.   See

Manrique, 581 N.E.2d at 1040; Panopoulos, 2001 WL 695106, at *1.

           We find these Massachusetts authorities equivocal, in

some respects pointing toward indivisibility, in others toward

divisibility.    The situation strikes us as one in which Mathis

suggests the court should consult Shepard documents to determine

if the crime is divisible.    And the absence of such documents in

or as a supplement to the record means that Bain cannot carry his

burden on plain error review.




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                              IV.

          For the foregoing reasons, we affirm Bain's conviction

and sentence.




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