Court Opinion

ID: 8209718
Source: CourtListenerOpinion
Date Created: 2022-09-27 21:00:37.741973+00
Date Added: 2024-06-11T16:41:44.010998
License: Public Domain

United States Court of Appeals
                      For the First Circuit

No. 21-1475

                          UNITED STATES,

                             Appellee,

                                v.

                           SEAN MULKERN,

                       Defendant, Appellant.

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

              [Hon. Jon D. Levy, U.S. District Judge]

                              Before

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

     John W. VanLonkhuyzen and Verrill Dana LLP on brief for
appellant.
     Darcie N. McElwee, United States Attorney, and Noah Falk,
Assistant United States Attorney, on brief for appellee.

                        September 27, 2022
            KAYATTA, Circuit Judge. This case arises from a parking-

lot   confrontation   following   a    road-rage   incident    between   the

driver of a white Corvette and several men in a landscaping truck.

Reports of that confrontation led law enforcement to stop Sean

Mulkern in his white Corvette the next day.              The subsequent

searches of Mulkern's vehicle and motor home yielded evidence

supporting drug-trafficking and firearms charges.             Mulkern moved

to suppress all of the evidence derived from what he argues were

illegal searches of his person and vehicles.          After the district

court denied that motion in relevant part, Mulkern pleaded guilty.

At sentencing, the district court found that Mulkern had three

prior qualifying offenses that rendered him subject to a mandatory

minimum sentence under the Armed Career Criminal Act (ACCA), 18

U.S.C. § 924(e).   Mulkern claims on appeal that the district court

erred first in denying his suppression motion and second in finding

him eligible for the ACCA sentence.        As we explain below, we see

no error on either score, so we affirm Mulkern's conviction and

sentence.

                                      I.

                                      A.

            The facts giving rise to this case unfolded over two

days in May 2017.       We recite those facts "in the light most

favorable to the district court's ruling" denying Mulkern's motion

to suppress, though we note Mulkern's "contrary view of the

                                  - 2 -
testimony presented at the suppression hearing" where relevant.

United States v. Sierra-Ayala, 39 F.4th 1, 6 (1st Cir. 2022)

(quoting United States v. Rodríguez-Pacheco, 948 F.3d 1, 3 (1st

Cir. 2020)).

                                    1.

          On May 24, 2017, Officers Warren Day and Jessica Ramsay

of the Buxton, Maine police department responded to a dispatch

call   reporting    a   possible     road-rage   incident   and   armed

confrontation. As relayed by the dispatcher, a man driving a white

Corvette with red rims had reportedly pulled a gun on a man at the

Timberline Country Store in Buxton. The dispatcher relayed a Maine

license plate number reported for the Corvette, "2512VW," but noted

that this number was actually registered to a black Lexus, rather

than a white Corvette.

          While en route to the Timberline, Officer Day spoke on

the phone with one of the reported victims, Scott Wallingford.

Wallingford, who had by that time left the Timberline and was on

his way to a job site, confirmed that the driver of a white Corvette

had displayed a gun and threatened him and his companions.

          When Officers Day and Ramsay arrived at the Timberline,

the Corvette was no longer present.        The officers spoke with two

store employees, who showed the officers a security video of the

confrontation.     According to Officer Ramsay's testimony at the

suppression hearing, the video depicted a white Corvette and a

                                   - 3 -
landscaping truck in the store's parking lot.                 Officer Ramsay

described the Corvette as "very distinct."         Three occupants of the

truck got out, approached the Corvette, and argued with its driver.

The driver of the Corvette then "reached into the back of the

Corvette and pulled something out -- it was difficult to tell what

it was at the time," and then held the object against his chest.

The three men on foot then "got elevated in their behavior";

"[t]hey started yelling and pointing" before the Corvette drove

off.

            One of the employees, Jaaron Thurlow, had been working

during the incident.      He spoke with the officers after they had

reviewed the video.      He recounted that he had seen three men in

the parking lot arguing with a fourth man in the driver's seat of

a white Corvette with two red stripes running from the front to

the back.    Thurlow said that the Corvette driver was in his 50s

and wore glasses.      He reported that the men yelled at each other

before the Corvette drove away and that the group of remaining men

then came into the store to talk to him.          As related by Thurlow,

the group told him that the Corvette had sped by them on the road,

that they followed him into the parking lot to confront him about

his dangerous driving, and that the Corvette driver had then pulled

a gun on them.

            On   the   basis   of   the   video   and   the    reports   from

Wallingford and Thurlow, Officer Ramsay requested that her station

                                    - 4 -
issue a "Caution Officer Safety" alert -- also referred to as a

"BOLO" (short for "be on the lookout") -- in a statewide law

enforcement system.   The BOLO read in full:

          ***     CAUTION     OFFICER    SAFETY     ***
          ON TODAY'S DATE BUXTON POLICE DEPARTMENT TOOK
          A REPORT OF A MALE IN A WHITE CORVETTE WITH
          RED RIMS WAS IN A ALTERCATION AT TIMBERLINE
          COUNTRY STORE 222 NARRAGANSETT TRAIL.     THE
          OPERATOR A MALE IN HIS 40'S WHITE SHIRT AND
          BALL CAP, PULLED OUT A HAND GUN AND SHOWED IT
          TO THE VICTIM.    THE VEHICLE WAS LAST SEEN
          HEADED TOWARD GORHAM.    IF LOCATED STOP AND
          IDENTIFY THE DRIVER.      THANK YOU FOR ANY
          ASSISTANCE.

                                 2.

          The next day, May 25, Patrol Sergeant Timothy Morrell of

the nearby Westbrook, Maine police department observed a white

Corvette with red rims, as described in the BOLO that he had seen

come in the previous day.   He testified at the suppression hearing

that, based on the distinctive nature of the vehicle, he thought,

"The odds of that being someone else are pretty slim."     When the

Corvette stopped and parked, Sergeant Morrell ran its license plate

number -- 2513VW -- and learned that it was registered to the

defendant, Sean Mulkern.    He was also able to see that the driver

appeared to be a man in his 40s with a baseball cap, as described

in the BOLO.

          He then called Buxton PD to inform them he believed he'd

located the vehicle from their notice.         Based on the vehicle

description and plate number, Buxton's police chief confirmed that

                                - 5 -
the sergeant had found the vehicle Buxton PD was investigating and

that his department would send officers out to speak with the

driver.      Sergeant Morrell acknowledged that, after the call with

Buxton PD, he did not believe that he personally had sufficient

information at that point to arrest Mulkern.

             In     the   meantime,    Sergeant   Morrell    ran   a   criminal

background check on Mulkern and learned that he had been convicted

of at least one felony and had a history of drug-trafficking

charges.      He also identified the driver he observed as Mulkern,

based   on    the    booking   photo   in   the   criminal   history   report.

Sergeant Morrell then called some other local officers to assist

with surveillance while waiting for Buxton PD.                 However, once

Mulkern got back into the Corvette and began to drive away,

Sergeant Morrell decided to change course and conduct a traffic

stop because he did not want Mulkern to get away.                  As Mulkern

pulled out of the driveway towards the direction of Sergeant

Morrell, he saw the sergeant and then turned hard in the other

direction.        Sergeant Morrell then activated his lights and pulled

Mulkern over.

             Sergeant Morrell and another Westbrook officer, Sergeant

Brian Olson, who had arrived to assist, then ordered Mulkern out

of the car and frisked him.            Sergeant Morrell started the frisk

but soon stopped so that he could secure the scene, letting

Sergeant Olson conduct the frisk instead.             Sergeant Olson felt a

                                       - 6 -
hypodermic needle in Mulkern's breast pocket and, when Mulkern

reached for the needle and began to attempt to explain that it was

his girlfriend's, the officers handcuffed him.                 Sergeant Olson

then proceeded with the frisk and discovered a cigarette package

in    another    pocket.     The    package's      outer   cellophane   wrapper

contained "white crystal rocks" that the officers believed to be

crack cocaine.

             At that point, according to Sergeant Morrell's testimony

at    the   suppression     hearing,      the   officers   believed   they   had

developed probable cause to search Mulkern's vehicle for evidence

of drug trafficking.        In conducting this search, they discovered

a backpack containing drugs, a gun, and over $13,000 in cash.

During the course of the frisk and vehicle search, Mulkern made

several incriminating statements:               He told the officers that the

rocks in the cigarette package were his; spontaneously shouted out

during the vehicle search that there was a gun in the car; and,

when officers found the backpack, stated something to the effect

of, "Yeah, you got it, that's it."

             Later that day, evidence derived from the traffic stop

and    vehicle    search,    as    well    as    information   provided   by   a

cooperating defendant, was used to obtain a search warrant for

Mulkern's Winnebago mobile home.                Law enforcement executed the

warrant that evening and discovered further drugs and guns in the

Winnebago.

                                       - 7 -
                                  B.

          A grand jury indicted Mulkern on three counts of drug

trafficking and firearms offenses.      Mulkern moved to suppress all

physical evidence and statements obtained from the stop under

several theories, including that the initial stop was an unlawful

seizure, that the subsequent search of his person exceeded the

bounds of a lawful pat-frisk, that the evidence obtained pursuant

to the ensuing search warrant for his Winnebago was tainted by the

earlier infirmities as so-called "fruit of the poisonous tree,"

and, finally, that several of his statements during the traffic

stop were the product of custodial interrogation without the

warnings required by Miranda v. Arizona, 384 U.S. 436 (1966).

          The district court agreed with Mulkern as to part of his

Fifth Amendment Miranda claim and suppressed any statements that

were prompted by the officers' questioning, while declining to

suppress statements Mulkern spontaneously offered.      No challenge

is pressed on appeal by either party to the district court's

resolution of that claim.1

          As to the search and seizure claims, the district court

denied Mulkern's motion.     While the court agreed that the search

     1  Mulkern does on appeal continue to seek suppression of all
of his statements to law enforcement during the stop, though he
does so on Fourth Amendment grounds, as the fruits of an unlawful
search and seizure, rather than on Miranda grounds. We therefore
consider the statements in our analysis of the Fourth Amendment
challenge.

                                - 8 -
of Mulkern's person would have exceeded the lawful bounds of a

pat-frisk if it could only have been justified on that basis, the

court upheld all of the searches on an alternative basis:                   Law

enforcement officers were justified in searching Mulkern's person

and vehicle as a search incident to arrest because they had

probable cause before the search to arrest Mulkern for being a

felon in possession of a firearm.

              Following the suppression ruling, Mulkern pleaded guilty

to counts one and three of the indictment, for, respectively:

(1) possession of cocaine base, cocaine hydrochloride, and heroin

with intent to distribute, in violation of 21 U.S.C. §§ 841(a)(1),

(b)(1)(B), and (b)(1)(C); and (2) being a felon in possession of

a firearm, in violation of 18 U.S.C. §§ 922(g)(1) and 924(a).2               He

reserved the right to appeal the denial of his motion to suppress.

              In its presentence investigation report, U.S. Probation

recommended that Mulkern be sentenced as an armed career criminal

on the basis of a 1994 Maine burglary conviction (as a "violent

felony")     and     two   2006   Maine    drug-trafficking   convictions   (as

"serious drug offense[s]").           Mulkern disputed his eligibility for

an ACCA sentence in briefing and at the sentencing hearing, but

the       district     court      ultimately      agreed   with   Probation's

      2 Count Two, possession of a firearm in furtherance of a drug
trafficking crime, was dismissed pursuant to an informal agreement
with the government.

                                          - 9 -
recommendation.3    The court varied downward from the sentencing

range provided by the U.S. Sentencing Guidelines and sentenced

Mulkern to ACCA's mandatory-minimum term of fifteen years of

incarceration.

                                   II.

          Mulkern challenges the denial of his motion to suppress

and his eligibility for an ACCA mandatory-minimum sentence.           We

consider these arguments in turn.

                                   A.

          In reviewing a district court's denial of a motion to

suppress, "we review legal conclusions de novo and factual findings

for clear error."      United States v. Batista, 31 F.4th 820, 823

(1st Cir. 2022).       While Mulkern argued for suppression under

several   constitutional      theories    below,   including   that   his

statements were obtained in violation of the Fifth Amendment's

prohibition against self-incrimination, his arguments on appeal

focus exclusively on purported Fourth Amendment violations, so we

train our attention accordingly.

                                   1.

          We   begin   with    background   principles   governing    our

assessment of Mulkern's suppression claim.         The Fourth Amendment

     3  We reserve further description of the predicate offenses
and the sentencing proceedings for our discussion of Mulkern's
sentencing claim.

                                 - 10 -
guarantees "[t]he right of the people to be secure in their

persons,   houses,      papers,    and   effects,   against     unreasonable

searches and seizures."      U.S. Const. amend. IV.      Thus, a search or

seizure by police does not offend the Fourth Amendment if that

conduct is "reasonable."        United States v. Rasberry, 882 F.3d 241,

246 (1st Cir. 2018).         The set of constitutionally permissible

seizures includes "a warrantless arrest by a law officer" when

"there is probable cause to believe that a criminal offense has

been or is being committed."         Devenpeck v. Alford, 543 U.S. 146,

152 (2004).      And, relatedly, the universe of constitutionally

reasonable searches includes warrantless searches incident to an

arrest, during which law enforcement may conduct "a full search of

the person" of an arrestee.         United States v. Robinson, 414 U.S.

218, 235 (1973).      Where an arrest follows a traffic stop, officers

may also search the arrestee's vehicle incident to the arrest "if

the   arrestee   is    within     reaching   distance   of    the   passenger

compartment at the time of the search or it is reasonable to

believe the vehicle contains evidence of the offense of arrest."

Arizona v. Gant, 556 U.S. 332, 351 (2009).

           The critical inquiry in many situations therefore trains

on whether police possess probable cause for an arrest, which may

then open the door to an incidental search.             Probable cause "is

not a high bar."      Kaley v. United States, 571 U.S. 320, 338 (2014).

"It 'requires only the kind of fair probability on which reasonable

                                    - 11 -
and prudent [people,] not legal technicians, act.'"        Rasberry, 882

F.3d at 250 (alteration in original) (quoting Kaley, 571 U.S. at

338).

          Police have probable cause to arrest when, "acting upon

apparently trustworthy information," they "reasonably can conclude

that a crime has been . . . committed and that the suspect is

implicated in its commission."        Karamanoglu v. Town of Yarmouth,

15 F.4th 82, 87 (1st Cir. 2021) (alteration in original) (quoting

United States v. Flores, 888 F.3d 537, 543 (1st Cir. 2018)).            For

example, the "[u]ncorroborated testimony of a victim or other

percipient   witness,   standing    alone,   ordinarily   can   support   a

finding of probable cause."     Id. at 87–88 (quoting Acosta v. Ames

Dep't Stores, Inc., 386 F.3d 5, 10 (1st Cir. 2004)).            Even where

a witness's account is disputed, "police officers do not have an

'unflagging duty' to complete a full investigation before making

a probable cause determination."        Id. at 88 (quoting Acosta, 386

F.3d at 11). Nevertheless, facts which otherwise may be sufficient

to establish probable cause can be overborne by contrary material

facts known to law enforcement.       Cf. Jordan v. Town of Waldoboro,

943 F.3d 532, 541–43 (1st Cir. 2019) (finding that correcting a

misrepresentation   and   two   material     omissions    in    a   warrant

affidavit "would have painted a fundamentally different picture"

which "would fall short of establishing probable cause").

                                   - 12 -
            We   review   probable-cause    determinations   objectively,

"asking whether the facts constitute probable cause of a crime,

rather than whether the officer thought they did."           United States

v. Monell, 801 F.3d 34, 40 (1st Cir. 2015); see also Devenpeck,

543 U.S. at 153 ("An arresting officer's . . . subjective reason

for making the arrest need not be the criminal offense as to which

the known facts provide probable cause.").

            When determining the universe of facts that we may

properly consider as the basis for probable cause, we may look to

"the collective knowledge of several officers."         United States v.

Cruz-Rivera, 14 F.4th 32, 44 (1st Cir. 2021).           Specifically, we

"look to the collective information known to the law enforcement

officers    participating     in    the     investigation    rather   than

isolat[ing] the information known by the individual arresting

officer."    Id. (alteration in original) (quoting United States v.

Azor, 881 F.3d 1, 8 (1st Cir. 2017)).

                                     2.

            With these principles in mind, we now take up Mulkern's

contention that the district court erred by failing to suppress

evidence from the traffic stop and ensuing searches.              Mulkern

argues that the officers did not have probable cause to arrest him

from the outset of the stop and that the search of his person

revealing the rocks of crack cocaine exceeded the bounds of a

lawful frisk under Terry v. Ohio, 392 U.S. 1 (1968).          As a result,

                                   - 13 -
he says, all evidence obtained from the traffic stop and ensuing

searches, including the statements he made during the searches and

interactions     with   law   enforcement,     were   obtained   unlawfully.

Moreover, because this evidence was used to obtain the search

warrant for the Winnebago, Mulkern argues that that evidence, too,

must be suppressed as so-called "fruit of the poisonous tree."

See,    e.g.,   Sierra-Ayala,   39    F.4th   at   16–19   (discussing   this

doctrine).

            Mulkern's arguments hinge on his contention that the

officers lacked probable cause to arrest him for being a felon in

possession of a firearm at the time they initiated the traffic

stop.    Cf. Batista, 31 F.4th at 823 (holding that, "if there was

probable cause for law enforcement to believe [the defendant] was

committing a crime when he was pulled over, there was no error in

denying the motion to suppress" evidence obtained from a search

during the traffic stop); Rasberry, 882 F.3d at 249 (affirming the

lawfulness of a search, originally conceived of as a frisk, where

the totality of circumstances gave the officer probable cause to

make an arrest before the search).            We conclude that the police

did have such probable cause and that Mulkern's claim accordingly

fails.

            The district court ably explained that the basis for

probable cause to believe Mulkern had committed a crime rested on

three factual determinations.         First, based on the facts available

                                     - 14 -
to the police, it would have been reasonable to believe the driver

of the white Corvette on May 24 possessed a gun.              Second, it would

have been reasonable to conclude that Mulkern was the driver of

that Corvette on May 24.          Third, they could reasonably conclude

that Mulkern was a felon at the time of that possession.                  Mulkern

has    conceded    the   third   point,    presumably    based    on   Sergeant

Morrell's    criminal-history          search   revealing     Mulkern's    felon

status, so we discuss only the first two conclusions.

            As to the first, the primary source supporting the

presence of a gun during the Timberline incident was Wallingford,

in his reports to the 911 dispatcher and then to Officer Day in

his initial telephonic interview.               The Timberline store clerk,

Thurlow, then also told Buxton police that Wallingford and his

companions had come into the store immediately after the Corvette

left and told him that they had been threatened with a gun.                  And

while Officer Ramsay could not confirm that what she saw on the

store's surveillance video was in fact a gun, she testified that

she did see the driver pull something from behind him and hold it

against his chest, leading the other men to display "elevated"

behavior towards him.

            Mulkern argues that Officer Ramsay did not definitively

identify a gun from the video and that the witnesses may not have

been    entirely    reliable     for    various    reasons,    including    that

Wallingford may have himself been the aggressor in the altercation

                                       - 15 -
and may have been motivated to minimize his own role.         But the law

does not require the police to have entirely reliable information

or absolute certainty when making a probable-cause determination

-- only "apparently trustworthy information,"            Karamanoglu, 15

F.4th at 87, and a "fair probability," Rasberry, 882 F.3d at 250

(quoting Kaley, 571 U.S. at 338).          Wallingford's account of a

brandished gun, as relayed to Officer Day over the phone, matched

what he had earlier conveyed to Thurlow and to the 911 operator in

his initial call.    These reports were all further corroborated by

the video's confirmation that some object was indeed brandished.

Objectively     viewed,   this   information     rendered   reasonable   a

determination that the driver of the Corvette on May 24 had a gun.

See Karamanoglu, 15 F.4th at 87–88.

           The second factual conclusion -- that Mulkern was the

Corvette's driver on May 24 -- strikes us as even more reasonable.

As a threshold matter, the same car clearly was involved on both

days.   Wallingford and Thurlow described, and the security footage

depicted, a white Corvette with distinctive features that all

substantially    match    Mulkern's   vehicle.    The   vehicle   Sergeant

Morrell saw the next day was fitted with a license plate number

just one digit off of what had been recorded by the dispatcher the

                                  - 16 -
prior day.4    Mulkern quibbles with some of the descriptions of the

vehicle provided by witnesses as insufficient to associate his

vehicle with the one at the Timberline, arguing that his rims are

only partially red and that the stripe on his car is black, rather

than the red striping reported by Thurlow.     But the officers were

hardly unreasonable in concluding that it was likely the witnesses

misapprehended those small details, rather than that there were

two white Corvettes with red trim and virtually identical non-

vanity plate numbers (and also a black Lexus with a duplicate of

the plate number given on May 24).

            Mulkern does not dispute that he was the driver on May 25

or that Sergeant Morrell accurately identified him before pulling

him over.     That tees up the question whether Mulkern was also the

driver on May 24.     Given that he was the registered owner of the

white Corvette, that he was driving the car in a neighboring town

the next day, and that there was no reason to think that he let

another man his approximate age in a ball cap drive his Corvette

on May 24, the police could reasonably conclude as part of their

probable-cause determination that Mulkern was indeed the driver on

both days.     Cf. Kansas v. Glover, 140 S. Ct. 1183, 1188, 1191

     4  Buxton Officer Ramsay testified at the suppression hearing
that, based on subsequent interviews with the victim-witnesses
from the Timberline, she believed the witnesses likely reported
the correct number -- 2513VW -- and that the number "g[ot] lost in
translation at some point," causing dispatch to "just change[] one
number of that plate" to 2512VW.

                                - 17 -
(2020) (knowledge that a person is the registered owner of a

particular pickup truck, absent other information, gives rise to

"an entirely reasonable inference" that the truck's driver is its

owner, even if the owner's license is revoked).

           To tie up a final loose end, it matters not that Sergeant

Morrell   did   not   subjectively   believe   that   he   personally   had

sufficient information to support probable cause to arrest Mulkern

when the officers initiated the search.        As we have explained, our

review of probable cause determinations is an objective inquiry,

unconcerned with the actual beliefs and motivations of the officers

on the scene.    See Monell, 801 F.3d at 40; see also United States

v. Guerrero, 19 F.4th 547, 553–59 (1st Cir. 2021) (surveying

Supreme Court and circuit precedent reiterating the objectivity of

Fourth Amendment inquiries).

           We therefore agree with the district court that the

Buxton and Westbrook police departments collectively possessed

sufficient information to reasonably conclude: (1) that the driver

of the white Corvette at the Timberline possessed a gun; (2) that

Sean Mulkern was that driver on May 24, 2017; and (3) that Mulkern

was at the time a convicted felon.         These conclusions provided

police with probable cause to arrest Mulkern for being a felon in

possession of a firearm, with the result that they could lawfully

search his person incident to an arrest.       That search of Mulkern's

person, if incident to an arrest, would also lawfully extend to

                                 - 18 -
any search of the cigarette package containing the crack cocaine.

See Robinson, 414 U.S. at 235–36 ("Having in the course of a lawful

search come upon the crumpled package of cigarettes, [the officer]

was entitled to inspect it; and when his inspection revealed the

heroin capsules, he was entitled to seize them."). Under the facts

of this case, that search incident to arrest could also permissibly

include a search of his vehicle, as police could search for

evidence of the crime of arrest -- namely, the gun reportedly seen

in the car the day before.     See Gant, 556 U.S. at 351.     And,

needless to say, if the evidence recovered from the traffic stop

was lawfully obtained, then there was no constitutional infirmity

in using that evidence to obtain the search warrant for the

Winnebago.   There was therefore no error in the district court's

decision denying Mulkern's motion to suppress.

                                B.

          We turn next to Mulkern's argument that he was improperly

sentenced under ACCA.   As we explain further below, close review

of the sentencing record compels us to find that Mulkern waived

the specific argument he now raises.    "[A] party waives a right

when he intentionally relinquishes or abandons it."   United States

v. Orsini, 907 F.3d 115, 119 (1st Cir. 2018) (quoting United States

v. Rodriguez, 311 F.3d 435, 437 (1st Cir. 2002)).   It follows that

when a litigant "explicitly affirms a fact in the district court,

that party risks waiving" his right to argue that the fact was

                              - 19 -
insufficiently established.        Id. (quoting United States v. Bauzó-

Santiago, 867 F.3d 13, 24 (1st Cir. 2017)).           "As a general rule,

a waived claim is unreviewable and, thus, cannot be revisited on

appeal."    Id.

            Of the three state convictions supporting the district

court's    ACCA   finding,   Mulkern   challenges    on   appeal   only    the

classification of his two Maine drug-trafficking convictions.               We

therefore begin with some background on our treatment under ACCA

of Maine's trafficking statutes, Me. Rev. Stat. Ann. tit. 17-A,

§§ 1101–1103.     Those statutes classify both cocaine and heroin as

"Schedule W" drugs, id. § 1102(1)(F), (I), and treat knowing or

intentional    trafficking    in   Schedule W   drugs     as   unlawful,   id.

§ 1103(1-A)(A).

            To qualify as ACCA-predicate "serious drug offense[s],"

these state-law trafficking crimes must have required proving at

least "possessi[on] with intent to manufacture or distribute" the

drugs.     See 18 U.S.C. § 924(e)(2)(A)(ii).        In the case of heroin

and fentanyl, Maine's trafficking regime at the time of Mulkern's

offenses allowed for a conviction in circumstances that do not

necessarily involve such intent.5        See United States v. Mulkern,

     5  The provisions treating heroin and fentanyl separately from
other drugs for trafficking purposes (formerly found at Me. Rev.
Stat. Ann. tit. 17-A, § 1101(17)(E) and (F)) were repealed in 2021,
though that does not affect Mulkern's appeal. See 2021 Me. Laws
ch. 396, § 1.

                                   - 20 -
854 F.3d 87, 95–96 (1st Cir. 2017).6              For that reason, a conviction

under that Maine law for trafficking heroin or fentanyl does not

categorically qualify as a "serious drug offense" under ACCA.                 Id.

at 97.          Conversely, in the case of cocaine (and most other

controlled substances), Maine's statutory regime does require the

jury to find distributive intent.                 See United States v. Mohamed,

920 F.3d 94, 104 (1st Cir. 2019).            Hence, a conviction under Maine

law for trafficking cocaine categorically qualifies as a serious

drug offense under ACCA.           Id.

                The record is clear that both parties and the court were

well familiar with the foregoing differential treatment under ACCA

between         a     conviction   under     Maine      law    for   trafficking

heroin/fentanyl and, as most relevant here, a conviction for

trafficking cocaine.            So, if defense counsel thought that the

government could not prove by proper evidence that the prior

convictions were for trafficking in cocaine, the apt argument was

readily apparent:          Such a failure would have required the court to

assume that the convictions did not involve an intent to distribute

and thus could not support an ACCA sentence.

                Instead of pursuing the cocaine/heroin dichotomy, the

defendant's sentencing memorandum started with the premise that

both       of   his   Maine   trafficking    convictions      "primarily   involve

       6The 2017 Mulkern case is unrelated to this proceeding,
despite the common surname.

                                         - 21 -
cocaine."         He    specifically      identified      as     the    "pertinent

trafficking statute" the one that "deal[s] with the 14 grams or

more   of   cocaine."         That    statute    allows   for     a    "permissible

inference" of intent to distribute based on the quantity of cocaine

possessed,    Me.      Rev.   Stat.     Ann.    tit. 17-A,       § 1103(3)(B),    a

mechanism which we held in Mohamed does not equate to taking the

question of intent away from the jury, contrary to the Maine regime

for heroin at the time.         See 920 F.3d at 104–05; see also Francis

v. Franklin, 471 U.S. 307, 314 (1985) ("A permissive inference

does not relieve the State of its burden of persuasion because it

still requires the State to convince the jury that the suggested

conclusion    should     be    inferred    based    on    the    predicate    facts

proved.").    Mulkern then argued that his conviction under that

statute did not qualify as an ACCA offense because, in his view,

"[a]ll that is required [under that statute], is that the possessor

possessed the requisite amount of cocaine, and nothing in the

available documents shows the Defendant in this case pled guilty

to intending to manufacture or distribute cocaine either."                       In

short, he first conceded that he was convicted of trafficking

cocaine, and      he   contended only       that our decision in            Mohamed

construing that offense as requiring a finding of distributive

intent was wrong.

            Defense counsel at sentencing continued to argue for

narrowing    or   rejecting     Mohamed's       holding   that    trafficking    in

                                       - 22 -
cocaine    under   Maine   law   was   an   ACCA-qualifying   serious   drug

offense.    Counsel noted that the district courts in Mohamed and

Mulkern, even with the benefit of so-called "Shepard proceedings,"7

ruled against the government.          In the course of that argument,

counsel stated that the particular Shepard documents filed at that

point in this case by the government "don't really give us much

information at all, other than confirming that Mr. Mulkern was

convicted of a drug trafficking offense under [Maine law]." Alert,

if not paranoid, government counsel promptly sought clarification.

            [GOVERNMENT COUNSEL]: . . . [B]ased upon the
            -- the sentencing memorandum filed by the
            defendant and the arguments presented in those
            filings, it was the Government's understanding
            that there's no dispute that the prior
            convictions involved cocaine, and so I wanted
            to confirm that that is not a disputed issue
            before I not offer any more exhibits.

            THE COURT: [Defense Counsel], is there any
            dispute on that question?

            [DEFENSE COUNSEL]: No, Your Honor.

            THE COURT: All right. So that is established,
            that they did involve cocaine.

            The government then went on to explain why it sought

this clarification, emphasizing that "it makes a difference what

drug we're dealing with" and that "[t]he drug matters," for the

     7  Shepard v. United States, 544 U.S. 13, 26 (2005), established
that a court considering an ACCA sentence may consult certain limited
documents relating to a divisible prior offense to determine whether
the defendant was convicted of a form of that offense that qualifies
as an ACCA predicate.

                                   - 23 -
reasons outlined above.            In the course of this explanation, the

government    explicitly       relied      on     its    perfectly     reasonable

understanding of Mulkern's concession, that the disputed offenses

"did involve cocaine" and "didn't involve heroin or fentanyl."

            The     court   summarized      the   government's       argument   as

essentially saying that "because the crime was cocaine, intent had

to be proven," before inviting defense counsel to respond to that

summary.    In doing so, defense counsel did not once mention heroin

or fentanyl, or in any way suggest that either prior conviction

was   or   could    have    been    for   trafficking    heroin   or    fentanyl.

Instead, he argued that Mohamed was wrong to hold that cocaine

trafficking under Maine law qualified as an ACCA serious drug

offense and urged the court to adopt the dissenting position in

that case.

            Having heard the foregoing, the district court noted

that it had to follow Mohamed since "this case involves cocaine,

a different drug" than the heroin involved in our 2017 Mulkern

decision.     The court then asked defense counsel "is there any

aspect of these legal issues I have not addressed that needs to be

addressed?"       "No," replied defense counsel.

            On appeal, Mulkern now points out that the Shepard

documents    that    the    government     did    file   in   reliance    on    his

concessions do not -- at least for one offense -- make clear

                                      - 24 -
whether the conviction was for trafficking cocaine or heroin.                    As

to his apparent waiver of this argument, he advances two theories.

            First, he contends that defense counsel did argue in the

district court that the Shepard documents (introduced by the

government) were insufficient to determine under which prong of

Maine's drug trafficking statute Mulkern was convicted.                         But

setting aside whether this form of the argument was ever actually

sufficiently articulated, the mere suggestion that defense counsel

may have been raising this very argument prompted the government's

request for clarification as to whether Mulkern was back-tracking

on his concession in his sentencing memorandum that the "pertinent

trafficking statute" was the one that "deal[s] with the 14 grams

or more of cocaine."        If so, the government reserved the right to

offer   additional    Shepard      documents.     Quite      plainly,    defense

counsel    then   assured    the   government    and   the    court     that    the

convictions involved cocaine.        Hence, no additional documents were

offered.

            Were there any doubt about the scope of the stipulation,

the   government   and   the    court   made    patently     clear    that     they

understood the defendant to be conceding that "both of these

convictions involve cocaine, trafficking cocaine, not trafficking

                                    - 25 -
heroin or fentanyl."            That natural reading of the concession,

understandably, prompted no protest from Mulkern's counsel.

              Picking at bits and pieces of what was said in the

district      court,    Mulkern    quotes     a    partial    sentence      from   his

sentencing      memorandum       stating,     "[N]othing       in   the     available

documents shows the Defendant in this case pled guilty to intending

to manufacture or distribute cocaine either."                   He contends that

this shows his argument below was broader than what we have

described.     But as we noted above, the full quoted sentence reads:

"All   that    is    required,    is   that       the   possessor   possessed      the

requisite amount of cocaine, and nothing in the available documents

shows the Defendant in this case pled guilty to intending to

manufacture or distribute cocaine either." In other words, counsel

was arguing that there was no support for a finding of intent to

distribute the cocaine, not that cocaine was not the object of the

charge.

              Mulkern    next    argues     that    although    both      convictions

"involved" cocaine, one also may have in fact involved some heroin.

Therefore, he reasons, the admission that the case involved cocaine

did not necessarily mean that the actual charge on which he was

convicted was for trafficking cocaine.                  This argument, too, fails

in context.         As we have explained, it is clear from the full

backdrop of the district court's question to counsel that the court

was not concerned with the nature of the conduct in fact, but

                                       - 26 -
rather the nature of the offense charged. In that context, defense

counsel at sentencing unequivocally assured the court that Mulkern

had been convicted of trafficking cocaine, and he then acquiesced

in repeated characterizations that the convictions did not involve

heroin or fentanyl.

          Citing United States v. Kennedy, Mulkern next points out

that "trial testimony" cannot fill a hole in the Shepard documents,

so his lawyer's admission of the "brute facts" of his prior offense

should not either.       See 881 F.3d 14, 23 (1st Cir. 2018).         But

Kennedy   refers    to   testimony   given   in   connection   with   the

adjudication of the prior conviction, not a concession later made

concerning the nature of that prior conviction.

          Considered within the context of the arguments in the

sentencing memorandum and at the hearing, the only plausible

conclusion is that Mulkern "explicitly affirm[ed] . . . in the

district court" that his prior convictions were for trafficking in

cocaine, the very fact whose finding he now questions.           Orsini,

907 F.3d at 119.     He has therefore "intentionally relinquishe[d]

[and] abandon[ed]" this argument, so we need not consider it on

the merits.   Id.

          To be sure, there are circumstances -- "hen's-teeth

rare" -- where we may in our discretion excuse a recognized waiver.

                                 - 27 -
Id. at 120.     Mulkern suggests in a footnote of his reply brief

that this is such a case.        We disagree.

           Excusing waiver may be appropriate where "the equities

heavily preponderate in favor of such a step."                Nat'l Ass'n of

Soc. Workers v. Harwood, 69 F.3d 622, 627 (1st Cir. 1995).                 We

also consider "whether the failure to advance an argument was

deliberate or inadvertent."       Sindi v. El-Moslimany, 896 F.3d 1, 28

(1st Cir. 2018).

           In this instance, Mulkern gives us no reason to think

that the waiver was the product any misunderstanding or error of

law.   Mulkern and his counsel very likely knew or could have

determined whether his prior offenses were not for trafficking

cocaine.   Nor was the waiver a slip of the tongue -- it was written

in the sentencing memorandum and then repeated and confirmed in

response to direct inquiry by the district court.                Indeed, the

argument that Mulkern made below proceeded from the very premise

he now contests.

           Notably, Mulkern even now does not assert that his prior

conviction    was   not   on   account   of   his   cocaine   dealing.    His

argument, instead, is that there is insufficient documentation to

prove that fact but for his concession.             So this is not a case in

which a waiver might have led the court to sentence under ACCA a

defendant who was not in fact within its scope.               In short, he is

in fact precisely the person that Congress wanted to receive an

                                   - 28 -
ACCA sentence, and his waiver waives no contention that he is not

that person.    Rather, it waives only the Sixth Amendment hurdle

that might have allowed him to avoid that classification.

           Our dissenting colleague misapprehends both our holding

and what happened in the district court.              Neither we nor the

district court have relied on any stipulation of law.         Nor did the

district court rely on just the Shepard documents before it.

Rather, the district court relied on Mulkern's agreement with the

prosecution concerning a key fact:            that the pertinent prior

convictions under Maine's drug distribution laws "did involve

cocaine" and "didn't involve heroin or fentanyl."             The entire

discussion in the district court was premised precisely on the

understanding that that fact was pivotal if Mulkern could not

convince the court that it should reject this circuit's holding in

Mohamed.

           Nor is there any reason that the district court need

have sought more Shepard documents given Mulkern's agreement that

his conviction was for selling cocaine.       F.R. Evid. 801(d)(2); cf.

United States v. Serrano-Mercado, 784 F.3d 838, 847 (1st Cir. 2015

(no   error    for   district   court    to    rely    on   "unchallenged

characterization" of a purported ACCA predicate); United States v.

Rios-Hernandez, 645 F.3d 456, 463 (1st Cir. 2011) (no clear and

obvious error for district court to rely on defendant's "apparent

acquiescence to the characterization of the prior convictions").

                                - 29 -
Were that not so, much of criminal practice in our district courts

would have to be revamped.    Nor was this, as the dissent argues,

a stipulation of law; it was a stipulation of fact: that he had

been convicted under Maine law of dealing cocaine.

          Even were we to excuse that waiver, we would still leave

Mulkern facing the burden of plain error review, which Mulkern

fails even to address in his main brief on appeal.       See United

States v. Rodriguez-Monserrate, 22 F.4th 35, 40 (1st Cir. 2021)

(holding that an argument "at best entitled to plain error review"

was waived where the appellant "ma[de] no attempt to satisfy that

standard" in his opening brief).

          Excusing that waiver as well, the dissent fashions a

bespoke version of plain error review that        fails to   account

successfully for our plain error cases.     In those cases, counsel

did not go so far as to affirmatively tell the judge that something

is so.   Rather, counsel only remained silent when something was

said to be so.   Even in that setting, though, we repeatedly placed

the burden on the appellant to at least represent that the missing

documents would support the forfeited position raised on appeal.

See Serrano-Mercado, 784 F.3d at 848; United States v. Davis, 676

F.3d 3, 10 (1st Cir. 2012); United States v. Turbides-Leonardo,

468 F.3d 34, 40 (1st Cir. 2006).        Here, where counsel was not

merely silent, but actually assured the court that the prior

conviction involved cocaine, it should follow a fortiori that the

                               - 30 -
defendant must at least do what we required in our other cases,

assuming that defendant was entitled to plain error review.

            The   dissent   tries    to      explain   its   more   favorable

treatment of Mulkern by pointing out that in his waiver he did not

expressly say that there were Shepard documents confirming that

the prior conviction was for trafficking cocaine.            This strikes us

as an immaterial distinction given that his more categorical waiver

-- in context -- subsumed the underlying facts concerning the state

records.    The prosecution's contention was that his conviction was

for dealing cocaine.    He challenged that contention only by saying

that even cocaine convictions did not qualify because Mohamed was

wrong.     And when asked, he said -- clearly, in context -- that he

was not challenging that it was a conviction for dealing cocaine.

So we do not think that we can say that all he did was neglect to

argue that the Shepard documents put in so far were themselves not

sufficient.

            The   observation   that      Mulkern      did   challenge   ACCA

applicability also strikes us as beside the point.             His challenge

was not that his prior conviction may have been for trafficking

heroin.    In context he clearly was agreeing that there was no need

for the government to do more to show that he had been convicted

of trafficking cocaine.     What he argued, instead, was the entirely

separate point that Mohamed was wrongly decided.              And that is an

argument that he would have made even if the record contained a

                                    - 31 -
court   document   unequivocally    attesting   to   his   conviction   for

trafficking cocaine.

           Finally, our dissenting colleague faults the government

for not arguing each prong of the plain error test.             But this,

too, overlooks the well-settled assignment of burdens, which do

not impose on the government the obligation to argue against each

prong of a test that the defendant did not even mention in his

opening brief and which would only be available to the defendant

were we to forgive his waiver.        See United States v. Rodríguez-

Torres, 939 F.3d 16, 40 & n.14 (1st Cir. 2019) (reiterating that

the party asserting plain error carries the burden of establishing

its elements and that efforts to do so for the first time in a

reply brief "come[] too late" and are waived).

                                    III.

           For the foregoing reasons, the decisions of the district

court are affirmed.

  - Opinion Concurring in Part and Dissenting in Part Follows -

                                   - 32 -
           BARRON, Chief Judge, concurring in part and dissenting

in part. The sentence that Thomas Mulkern received under the Armed

Career Criminal Act ("ACCA") is both mandatory and long.                    It is

also plainly not supported by the sole evidence that the District

Court relied on to impose it -- namely, the only official documents

from Mulkern's state-court criminal proceedings that the District

Court "received" during the federal sentencing proceedings.                      For

that reason, it is not a sentence that has been lawfully imposed.

           The   majority      concludes    otherwise       based    on   what   it

describes as Mulkern's stipulation of fact to the District Court.

But, as I will explain, the stipulation that the majority has in

mind was one of law, rather than fact.        Accordingly, I cannot agree

that any stipulation that Mulkern may be deemed to have made below

bars us from considering his legal argument for overturning his

sentence due to a lack of supporting evidence for it.                And, because

that   legal   argument   is    plainly    correct,     I    would    vacate     his

sentence, although I agree with the majority that his conviction

must be affirmed.

                                     I.

           Mulkern's sentencing challenge on appeal focuses on what

he contends is the evident inability, as a matter of law, of the

so-called Shepard documents on which the District Court relied to

provide the evidentiary basis for the mandatory, 15-year prison

term that is at issue.      Shepard v. United States, 544 U.S. 13, 26

                                   - 33 -
(2005) ("We hold that enquiry under the ACCA to determine whether

a plea of guilty to burglary defined by a nongeneric statute

necessarily admitted elements of the generic offense is limited to

the terms of the charging document, the terms of a plea agreement

or transcript of colloquy between judge and defendant in which the

factual basis for the plea was confirmed by the defendant, or to

some comparable judicial record of this information.").                     Those

documents consist of the official records from the state criminal

proceedings     in   which    Mulkern    was     convicted       of   two    drug

"trafficking" crimes under Maine law.

          The    government    submitted       the    Shepard    documents      at

Mulkern's federal sentencing proceedings to establish that he had

been convicted of three ACCA-qualifying convictions at the time of

his firearms possession, thereby requiring the imposition of the

ACCA's   mandatory    fifteen-year      prison       sentence.        18    U.S.C.

§ 924(e)(1).     The government contended based on those specific

documents that Mulkern had been convicted not only of a "violent

felony" within the meaning of the ACCA, due to a prior Maine-law

burglary conviction that he had received, but also of two "serious

drug offense[s]" within the meaning of that same statute, due to

the two Maine-law drug "trafficking" convictions that he had

received as well.     Id.

          Mulkern does not dispute on appeal that he was convicted

of a "violent felony" within the meaning of the ACCA based on his

                                  - 34 -
burglary conviction.      But, he argues that, as a matter of law, the

Shepard documents regarding the two drug "trafficking" convictions

that the government submitted fail to show that he had been

convicted of two "serious drug offense[s]."               Those documents, he

contends, show at most that he had been convicted of one "serious

drug offense," leaving him with only two (rather than the required

three)_convictions that qualify as predicate convictions under the

ACCA.

            Mulkern points out that the relevant Shepard documents

consist solely of his two judgments of conviction for violating

Maine's drug "trafficking" statute.          See Me. Rev. Stat. Ann. tit.

17–A, § 1103(1-A)(A).     He then observes that, at the time of those

convictions,   that   Maine   statute       set   forth     a       divisible   drug

"trafficking" offense, as that statute set forth two separate drug

"trafficking" crimes -- one cocaine-based and one heroin-based.

See United States v. Mohamed, 920 F.3d 94, 104-105 (1st Cir. 2019).

            Mulkern contends that this feature of the Maine statute

is significant because we have held that only one of those two

state-law   "trafficking"     crimes   qualifies       as       a    "serious   drug

offense"    under   the    ACCA.       18     U.S.C.      § 924(e)(2)(A)(ii).

Specifically, he rightly notes that we have held that the one for

"trafficking" cocaine does qualify, see Mohamed, 920 F.3d at 104-

105, while the one for "trafficking" heroin does not, see United

States v. Mulkern, 854 F.3d 87, 96-97 (1st Cir. 2017).

                                   - 35 -
           Thus, Mulkern contends that the Shepard documents that

the government submitted -- namely, the two judgments of conviction

for his Maine drug "trafficking" crimes -- in and of themselves

can suffice to show, legally, that he had been convicted of two

"serious drug offense[s]" only if each judgment of conviction

specifies on its face that it is for the ACCA-qualifying, cocaine-

based "trafficking" offense. For, only then could those documents,

by   themselves,    show   that   neither   of   his   drug   "trafficking"

convictions    is    for    the     non-ACCA-qualifying,       heroin-based

"trafficking" offense.      Mathis v. United States, 579 U.S. 500, 519

(2016) ("Of course, such record materials will not in every case

speak plainly, and if they do not, a sentencing judge will not be

able to satisfy '[the] demand for certainty' when determining

whether a defendant was convicted of a generic offense." (quoting

Shepard, 544 U.S. at 21)).        And, Mulkern goes on to argue, one of

those two judgments of conviction fails to provide the necessary

indication that it was for the cocaine-based "trafficking" crime.

           Mulkern does acknowledge that the record before us also

contains a description of the conduct in which he was engaged when

he committed the Maine "trafficking" offenses for which he was

convicted.     That description is set forth in the Pre-Sentence

Report ("PSR") that the U.S. Office of Probation prepared in

advance   of   Mulkern's    federal    sentencing.       Mulkern   further

acknowledges that he did not object to that description of his

                                   - 36 -
criminal conduct in his federal sentencing proceedings, and he

does not dispute the accuracy of that description on appeal.

               But, Mulkern points out that the description of his past

conduct    in    the     PSR    shows   only      that,   as   to     one    of   the   two

"trafficking" convictions, he was engaged in "[t]rafficking in

[s]cheduled [d]rugs" and that, per the PSR, the conduct underlying

that offense involved both cocaine and heroin.                       Thus, he contends

that, based on that description of his underlying criminal conduct,

he     could    have     been    charged       under      Maine      law    either      with

"trafficking" cocaine or "trafficking" heroin.                       Mulkern therefore

contends that, even when the PSR's undisputed description of his

criminal       conduct    is    combined     with      the   relevant        judgment    of

conviction for drug "trafficking" that is in the record, nothing

shows that that Maine drug "trafficking" conviction is for the

ACCA-qualifying, cocaine-based "trafficking" offense.

               In consequence, Mulkern contends that, as a matter of

law, the record fails to establish that he is subject to the

mandatory fifteen-year sentence that the ACCA requires, because

there is simply no document in the record that, as a matter of

law,     could     establish         that    he     had      three     ACCA-qualifying

convictions -- rather than, at most, two, based on his prior

burglary       conviction      and   his    conviction       for    one     cocaine-based

"trafficking" offense -- at the time of his firearms possession.

Thus, he contends, the record does not permit the ACCA's mandatory,

                                           - 37 -
15-year prison sentence to be imposed on him until the government

augments that record with additional documents from Mulkern's

state court criminal proceedings that the District Court has not

yet seen.

                                   II.

            Of course, as the government asserts, and the majority

concludes, Mulkern did not make this potentially winning argument

below.     He argued at his federal sentencing proceedings only that

he could not be subjected to the ACCA's mandatory, fifteen-year

prison sentence even if the record sufficed to show that he had

been convicted twice for the cocaine-based variant of the state-

law "trafficking" offense.      That was because, he contended in the

District Court, we were wrong, as a matter of law, to have held in

Mohamed that such a cocaine-based "trafficking" crime under Maine

law is itself a "serious drug offense" under the ACCA, 920 F.3d at

104-105, given the reasons that we gave in an earlier case for

holding    that   the   heroin-based   variant   of   that   "trafficking"

offense is not, Mulkern, 854 F.3d at 96-97.

            I happen to agree with Mulkern that Mohamed was wrongly

decided.     See Mohamed, 920 F.3d at 107 (Barron, J., dissenting).

But, this panel, like the District Court, has no power to disregard

a controlling precedent of this Circuit.         Thus, we have no choice

but to reject the legal argument that Mulkern made below based on

Mohamed, just as the District Court had no choice but to do so.

                                 - 38 -
          The key question for us on appeal therefore reduces to

this: does Mulkern's failure to make a potentially winning argument

to the District Court about the legal deficiency of the record on

which the District Court relied in imposing his sentence bar him

from making that same argument to us on appeal?       The majority

concludes that it does, given the way that it understands Mulkern

to have presented his case below.      It emphasizes in this regard

that Mulkern's counsel agreed when questioned by the District Court

that -- based on what the Shepard documents that had been given to

the District Court showed -- the drug "trafficking" convictions at

issue were for the cocaine-based rather than the heroin-based

variant of the drug "trafficking" crime.

          That said, it is not always easy to distinguish the

knowing abandonment of an argument (waiver) from the failure to

make one (forfeiture).   See United States v. Antonakopoulos, 399

F.3d 68, 76 n.7 (1st Cir. 2005); United States v. Campbell, 26

F.4th 860, 871 (11th Cir. 2022) (en banc).       And, I am not as

confident as the majority that Mulkern's defense counsel was

knowingly giving up a seemingly strong argument in pressing the

alternative one that he wrongly thought was even better.

          Nonetheless, the majority recognizes that a waiver may

be excused in rare cases.   United States v. Orsini, 907 F.3d 115,

120–21 (1st Cir. 2018) (explaining that a defendant's waiver can

be excused when the "equities heavily preponderate in favor of

                              - 39 -
such a step," and that "[i]n deciding whether an exception is

warranted,   we   may   consider   factors   'such   as   whether   the

inadequately preserved arguments are purely legal, are amenable to

resolution without additional factfinding, are susceptible to

resolution without causing undue prejudice, are highly convincing,

are capable of repetition, and implicate matters of significant

public concern'" (quoting Nat'l Ass'n of Soc. Workers v. Harwood,

69 F.3d 622, 627 (1st Cir. 1995) then Sindi v. El-Moslimany, 896

F.3d 1, 28 (1st Cir. 2018))).      And so, in what follows, I assume

that the majority is right to conclude that we are dealing with a

waiver rather than a forfeiture, because I see no reason not to

excuse the waiver insofar as there was one.

          I must emphasize, though, that my disagreement with the

majority is about more than the circumstances in which a waiver

may be excused. It also concerns how to understand what transpired

below.

          The majority does not appear to be of the view that

Mulkern waived the legal argument that he now makes to us merely

because he took the opposite legal position below.        The majority

instead appears to be of the view that Mulkern waived that legal

argument by stipulating to the District Court (even if only

implicitly) that, as a matter of fact, there were Shepard documents

in existence that, unlike the ones that the government submitted

in the federal sentencing proceedings, would suffice, as a matter

                                - 40 -
of law, to show that Mulkern was twice convicted of the cocaine-

based,   rather   than   the   heroin-based,   variant   of   the    drug

"trafficking" crime under Maine law.

          But, as I will explain, I cannot agree that Mulkern made

any such factual stipulation.     As a result, I cannot see how the

representations that he made below preclude him from successfully

arguing to us that, as a matter of law, at least one of his prior

drug "trafficking" convictions was not for what the ACCA deems to

be a "serious drug offense."

                                   A.

          The majority does not dispute that the waiver of an

argument about a "purely legal question," as opposed to the waiver

of a contention about a question of fact, may be excused.           Sindi,

896 F.3d at 28. And, in my view, Mulkern did waive only an argument

about a purely legal question.

          The only evidence that the District Court identified as

providing support for its determination that the ACCA sentencing

enhancement applied to Mulkern consisted of the Shepard documents

described above -- namely, Mulkern's two judgments of conviction

for drug "trafficking" under Maine law.         Indeed, the District

Court was quite clear during Mulkern's sentencing hearing that it

was only the Shepard documents that it had "received" that provided

the evidentiary basis for the determination that Mulkern had the

requisite number of qualifying convictions under the ACCA.

                                 - 41 -
            Thus, we need not engage in any fact-finding to determine

whether there is merit to Mulkern's supposedly waived argument

regarding the insufficiency of the evidentiary basis for the

imposition of the ACCA's mandatory 15-year prison sentence.                  We

need only apply the law to the undisputed facts by examining those

precise Shepard documents in the record on which the District Court

relied and determining whether, as a matter of law, they show what

they must under Mathis.      See Mathis, 579 U.S. at 519.

                                        B.

            Mulkern's    purely    legal     contention   is     also   "highly

convincing."      Orsini, 907 F.3d at 120–21.          As I have explained,

the only Shepard documents that pertained to drug offenses that

the District Court "received" show no more than that each of

Mulkern's state-law drug "trafficking" convictions was for an

offense that was set forth in a statute that set forth two separate

crimes, only one of which qualifies under the ACCA as a "serious

drug offense."     Moreover, the unobjected-to PSR does not describe

the conduct by Mulkern that underlies one of these two convictions

in   a   manner   that   could   show    what   the   relevant    judgment   of

conviction itself plainly does not -- that it was for the cocaine-

based "trafficking" crime rather than for the heroin-based one.

            So, under Mathis, the record plainly is not sufficient,

as a matter of law, to show that Mulkern did have three prior ACCA-

qualifying convictions.      Instead, the record at most shows that he

                                   - 42 -
had only two such convictions -- the one for a "violent felony"

based on his conviction for burglary and the other for a "serious

drug offense," based on a drug "trafficking" conviction under Maine

law for "trafficking" cocaine.         Indeed, I cannot see what possible

argument there could be to the contrary, given that there is no

dispute that a conviction for "trafficking" heroin under Maine law

is not a "serious drug offense" under the ACCA.

            I do recognize that in other cases we have held that

defendants could not show plain error in arguing for the first

time on appeal against the application of federal sentencing

enhancements based on their contentions that the government had

failed to submit adequate Shepard documents at their federal

sentencing proceedings.       See United States v. Serrano-Mercado, 784

F.3d 838 (1st Cir. 2015); United States v. Davis, 676 F.3d 3 (1st

Cir. 2012); United States v. Turbides-Leonardo, 468 F.3d 34 (1st

Cir. 2006).      But, those cases are not like this one.

            The defendants in those cases had acquiesced, through

their silence at their federal sentencing proceedings, to the

characterization        of   the    offenses    underlying     their    prior

convictions that had been set forth in the PSRs.          On appeal, those

defendants did correctly point out that there were no Shepard

documents   in    the   record     sufficient   to   support   the   relevant

enhancements to their sentences.              Nonetheless, we interpreted

their silence at sentencing to indicate that some Shepard documents

                                     - 43 -
existed that, although not in the record before the sentencing

courts, would support the enhancements in question.              We thus

declined to presume on appeal in those cases that, as matter of

fact, those extra-record Shepard documents -- if revealed -- would

show something other than what the defendants seemed to accept

that those documents would show through their failure to challenge

the PSR's characterization of the nature of the offenses underlying

their prior convictions.      After all, there was good reason (based

on the defendants' silence in the face of the PSR) to think the

defendants were stipulating, as a matter of fact, that Shepard

documents that would provide the evidentiary basis for their

sentence could be produced.      See Serrano-Mercado, 784 F.3d at 848

(noting that there, like Davis, the defendant had not objected to

either the PSR's or the sentencing judge's characterization of the

offense, and as a result, "[t]he District Court thus had no Shepard

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

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

report's   assertion   that   the   enhancement   applied   or   on   the

defendant's apparent agreement with that assertion").

           Here, however, Mulkern did not at any point suggest in

the proceedings below -- through a failure to object to the PSR's

characterization of the statutory offense of conviction -- that

there was in fact some document from his state court proceedings

that had not been entered into the record but that when produced

                                 - 44 -
would reveal what the documents from those state proceedings that

were in the record did not.   As we have seen, the PSR did not even

characterize one of Mulkern's two, prior "trafficking" convictions

as being for "trafficking" cocaine. The PSR stated in the relevant

respect only that Mulkern had been convicted of "trafficking" a

"controlled substance" and that that conviction qualified as an

ACCA predicate.

          Moreover,   the   PSR    also    did   not   describe   Mulkern's

conduct in committing one of the state-law drug "trafficking"

crimes of which he was convicted in a way that would require us to

conclude that the conviction based on that conduct must have been

for the cocaine-based variant of the Maine "trafficking" offense.

As Mulkern convincingly explains, the description of his conduct

in the PSR refers to his having been in possession of both heroin

and cocaine.   In other words, he seemingly could have been charged

based on that conduct with either the cocaine- or heroin-based

variant of Maine's drug "trafficking" offense. Thus, while Mulkern

did not dispute that description during the sentencing hearing

below, his failure was not a stipulation to the factual nature of

his conduct that would compel the conclusion that he was convicted

for that conduct of "trafficking" cocaine rather than heroin.

          Notably, my understanding of what transpired below is

not just my own.   The government does not itself contend (as the

majority necessarily does in relying on the claimed stipulation)

                                  - 45 -
that Mulkern, at any point, suggested through either what he did

say or what he did not that there were any damning, extra-record

Shepard documents out there that had not been submitted to the

District Court.   And, indeed, the District Court also appears to

have understood Mulkern's position at sentencing to have been

merely that, because Mohamed was wrongly decided, the specific

Shepard documents that had been entered into the record as to at

least one his two drug "trafficking" convictions did not suffice,

as a matter of law, to establish that he had been convicted of a

qualifying offense under the ACCA even if the conviction was for

"trafficking" cocaine.

          Thus, the District Court did not suggest that there was

any factual stipulation by Mulkern to there being extra-record

Shepard documents that would supply the evidentiary support for a

15-year mandatory prison sentence under the ACCA.     The District

Court concluded only that the     Shepard   documents that it had

"received" supplied that evidentiary basis, given that Mohamed was

a controlling precedent.

          So, to the extent that the District Court was misled by

Mulkern due to the argument that he made below about what the

Shepard documents in question sufficed to show about the type of

"trafficking" crime of which he had been convicted, the District

Court was misled solely about a point of law, not a matter of fact.

For, in crediting the notion that the Shepard documents that it

                              - 46 -
had "received" in and of themselves sufficed to show that Mulkern

had been convicted twice of "trafficking" cocaine -- and thus that

those documents in and of themselves sufficed to show that Mulkern

was subject to the ACCA's fifteen-year, mandatory minimum prison

sentence -- the District Court was necessarily making a legal

rather   than   a   factual    judgment    about   what    those     documents

demonstrated.

           In other words, I do not take issue with the majority's

suggestion that a defendant (by implication) may be deemed to have

stipulated to a fact and thereby to have obviated the need for the

government to put forth evidence to prove that fact.                 I merely

conclude that we have no such stipulation of fact here.

           Mulkern    did     stipulate    that    the    specific     Shepard

documents that the government submitted to the District Court --

namely, the two judgments of conviction for drug "trafficking" --

showed that he had two prior convictions for "trafficking" cocaine.

But, Mulkern did not thereby make the factual stipulation that he

had been twice convicted of "trafficking" cocaine that the majority

attributes to him.     Instead, the record shows that, by agreeing

that the Shepard documents before the court sufficed under Mathis

to show that he had been twice convicted of "trafficking" cocaine,

Mulkern was making only a stipulation of law concerning the legal

sufficiency of those documents to reveal that the underlying

offense was cocaine-based.       But, as I have explained, in light of

                                  - 47 -
Mathis,    that    legal    stipulation        was     plainly    wrong,    given      the

divisible nature of the statute setting forth that offense and the

facially inconclusive nature of the judgments of convictions that

the government entered into the record below.

            I do recognize that the government contends that, even

if we were to excuse Mulkern's waiver below of any challenge to

whether the submitted Shepard documents could establish, as a

matter of law, that he had twice been convicted of "trafficking"

cocaine,    we    still    would     confront      a    waiver    on     appeal.       The

government contends in this regard that Mulkern has waived on

appeal any argument that he can show that the District Court

plainly    erred    in     relying     on   the      Shepard     documents      that    it

"received" to conclude that the government had met its burden to

show that he had been convicted of not just one but two prior

"serious drug offense[s]" within the meaning of the ACCA.                              See

Serrano-Mercado, 784 F.3d at 845.                 But, I cannot see how that is

so.

           Mulkern argued to us in his opening brief that he raised

the   Mathis-based       argument      below    that     he    advances    on   appeal.

Understandably, then, he did not in that brief address the plain

error   standard,    as     he   was    asserting       that     there    had   been    no

forfeiture at all.          Moreover, after the government contended on

appeal that Mulkern did not in fact raise the Mathis-based argument

at his federal sentencing proceedings, he filed a reply brief in

                                        - 48 -
which he argued both that there was no waiver of that argument and

that there was at most only a forfeiture of it.                    He then further

argued that, insofar as there was a forfeiture, he could meet the

plain error standard.

            So, when confronted with the contention that there was

a forfeiture, Mulkern argued to us how he could overcome it.                         He

did so by asserting that the District Court made a clear or obvious

error in treating the Shepard documents that it had "received" as

legally    sufficient      to   show    that     he   been   twice    convicted      of

"trafficking"      cocaine;     that    such     treatment    prejudiced      him    by

triggering    the   imposition      of    a    mandatory     and    lengthy   prison

sentence;    and    that    the   error       would   "seriously     impair[]       the

fairness,     integrity,        [and]     public      reputation      of   judicial

proceedings."       United States v. Rivera-Morales, 961 F.3d 1, 12

(1st Cir. 2020).

            Moreover, I note that the government does not dispute

that Mulkern has satisfied the prejudice prong of the plain error

test.     It contends only that he fails to meet the other prongs of

that test. But, that contention is unpersuasive, given the perfect

clarity of the legal error here and the evident injustice of

permitting a defendant to be subject to a fifteen-year mandatory

prison sentence due to such a clear legal error.                   I add only that,

in holding the government to its own apparent view that, if there

were a clear or obvious error, Mulkern was prejudiced by it, I am

                                        - 49 -
hardly innovating.       See United States v. Paulino-Guzman, 807 F.3d

447, 450 n.5 (1st Cir. 2015) ("'[W]hen the government fails to

request plain error review,' we may 'review the claim under the

standard of review that is applied when the issue is properly

preserved below.'" (citing United States v. Encarnación–Ruiz, 787

F.3d 581, 586 (1st Cir.2015))).

           For   these    reasons,    I    cannot   agree    that      our   prior

precedents in this realm preclude Mulkern from showing plain error

here.   None of them involved, as this one does, a sentencing judge

expressly identifying the specific documents that served as the

evidentiary   foundation     for     the   application      of   the    relevant

sentencing enhancement when those documents patently provide no

such foundation.     Nor are any of those cases ones in which the

government failed to dispute the defendant's contention that he

was prejudiced by being subjected to a sentencing enhancement on

such a barren record.      Accordingly, those cases fail to show that

we should not excuse the waiver that the majority contends occurred

insofar as it means to suggest that the legal argument that Mulkern

now asks us to consider is less than "highly convincing."

                                      C.

           I recognize that even when a waived argument concerns a

purely legal contention that is highly convincing, we must take

account of any possible prejudice to the non-waiving party of our

excusing the waiver.       But, in asserting that Mulkern is bound by

                                   - 50 -
the mistaken legal position that he took below, the government

does not suggest that Mulkern gained an edge by keeping additional

evidence of his conduct hidden from the District Court at his

federal sentencing.      Nor does the government contend that there

were other Shepard documents that were once available but that

have since been lost to time.        The government thus does not contend

that Mulkern's failure to require the government to show its hand

in the federal sentencing proceedings prejudiced its ability to

make   a   strong   showing   that    his     two   drug-related,   Maine-law

convictions were both for ACCA predicate offenses.

            Rather, the government maintains on appeal that there

are other Shepard documents from Mulkern's state court proceedings

that were not entered into the record at his federal sentencing

proceedings in the District Court, that it has those very documents

in hand, and that it is prepared to reveal them now if asked.             The

government even notes that it would have shown them to the District

Court if Mulkern had not agreed that the documents that it had

entered into the record sufficed to show that he had been convicted

twice of "trafficking" cocaine.         How hard would it be, then, for

the government to make those as-yet-unseen documents part of the

record at this stage of the litigation, whether on appeal or in

the District Court on remand, so that a court could then determine

whether one of Mulkern's drug "trafficking" convictions in fact is

for "trafficking" heroin?

                                     - 51 -
              In sum, the government is best positioned to know whether

it would be prejudiced if we were to excuse the waiver.                          Yet, it

develops no argument as to how it would be prejudiced if we were

to accept its own offer to have a court look at the mystery Shepard

documents that it contends that it holds.                   I thus cannot see any

basis for concluding that our obligation to ensure that we treat

the non-waiving party fairly requires that we refuse to consider

Mulkern's meritorious legal contention under Mathis in deciding

whether to affirm his federal sentence.

                                            D.

              I    come,   then,     to   the    final    prong    of   the     test   for

determining whether to excuse the waiver.                  That prong, like prong

four of the plan error test, asks us to reflect on the relationship

between   a       decision    as     to   whether    to   excuse      the   waiver     and

confidence in the judicial system.                But, here, as well, I see more

reason to excuse the waiver than not to do so.

              The doctrines of waiver and forfeiture play an important

role in ensuring an orderly process of appellate adjudication.

See Orsini, 907 F.3d at 119.               But, they exist to facilitate, not

thwart, the dispensing of justice.                  See, e.g., United States v.

Torres-Rosario, 658 F.3d 110, 116 (1st Cir. 2011) (excusing a

defendant's waiver of objection to his ACCA sentence enhancement

because   the      plain     error    standard      was   met   and     there    was   "no

threat . . . of unfair prejudice to the government").

                                          - 52 -
           The government has no legitimate interest in advocating

for the imposition of a sentence pursuant to the ACCA if there are

no Shepard documents that suffice to support the imposition of

that sentence.    And, the government has not explained how it would

be prejudiced if we were to make it do what it has not yet

done -- show a court evidence that could suffice to establish that

Mulkern was convicted of two, rather than just one, "serious drug

offense[s]" within the meaning of the ACCA.       Thus, I do not think

that it reflects well on our system of criminal justice to affirm

the   mandatory   fifteen-year-long   prison   sentence   in   this    case

without first requiring a court to review the only evidence (if

any there be) that could supply the missing record support for the

imposition of that sentence.

           We have been careful in our past cases to ensure that

defendants facing sentencing enhancements based on convictions

arising out of state criminal statutes that set forth divisible

offenses are not incentivized to hold back contentions about

deficiencies in the record to gain strategic advantage.               Thus,

when such defendants have led a sentencing judge to believe that

there is extra-record evidence that would cinch the case for

applying the relevant sentencing enhancement, we have been wary of

permitting those defendants to reverse course on appeal by crying

foul that no such evidence had been entered at sentencing.

                                - 53 -
          Mulkern did not engage, however, in any such strategy.

He staked his challenge to the imposition of the ACCA-based

enhancement below on a mistaken legal contention about certain

specific Shepard documents that had been submitted to the District

Court.   He now wishes to press the purely legal, and plainly

correct, contention that he did not make at that time -- namely,

the contention that those documents fail as a matter of law to

show what they must.    As that contention is clearly a winning one,

I can see little justice in affirming a sentence that, as the

record presently stands, provides no basis for concluding that it

is a sentence that lawfully may be imposed on him.

                                    III.

          For   these   reasons,    I   respectfully   dissent   from   the

majority's decision to affirm the sentence below, although I join

fully in the rest of the majority's analysis.

                                   - 54 -