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DISTRICT OF COLUMBIA COURT OF APPEALS
No. 24-CF-1015
MARVIN W. LOPEZ, APPELLANT,
V.
UNITED STATES, APPELLEE.
Appeal from the Superior Court of the District of Columbia (2016-CF1-018780)
(Michael K. O’Keefe, Judge)
(Submitted March 17, 2026 Decided July 30, 2026)
Peter H. Meyers was on the briefs for appellant.
David P. Saybolt, Assistant United States Attorney, with whom Jeanine Ferris Pirro, United States Attorney, and Chrisellen R. Kolb, Kristian L. Hinson, and Sarah Prins, Assistant United States Attorneys, were on the brief for appellee.
Before EASTERLY, DEAHL, and SHANKER, Associate Judges.
DEAHL, Associate Judge: Marvin Lopez was charged with killing Evelyn
Yamileth Arrollo Guerra, his girlfriend who had recently broken up with him, on
Christmas Eve of 2014. He was convicted of first-degree murder and a related 2
firearm offense, and he now raises one challenge to his underlying convictions and
two challenges to his sentence.
Lopez’s challenge to his convictions relates to testimony from the
government’s expert on intimate partner violence. Defense counsel objected to the
expert’s proposed testimony in its entirety, but the government argued that its expert
would offer testimony that was relevant (1) to helping the jurors understand why
Arrollo would stay with Lopez, who was an allegedly abusive partner during their
relationship, and (2) to further explain “why a relationship may become more lethal”
when the victim “successfully ends the relationship with the abuser.” The trial court
permitted the expert to testify on the first topic but not the second.
Despite the court’s ruling, the government’s expert made two stray comments
that violated the court’s restrictions on her testimony. The more salient comment
was that the expert briefly alluded to a study that concluded abuse is most likely to
turn deadly either just before or just after a breakup, which mapped onto the
government’s allegations in this case that Lopez killed Arrollo shortly after their
breakup. Defense counsel objected to that testimony and successfully moved to
strike it from the record, but Lopez contends on appeal that was an insufficient
remedy. He now argues that this testimony was so prejudicial that the trial court had
no choice but to sua sponte declare a mistrial. We disagree for two reasons: (1) our 3
review of this unpreserved claim is for plain error, and when the government
introduces improper testimony that unduly prejudices a defendant, we doubt it is
ever plain error to not declare a mistrial that the defense has not requested; and (2) in
any event, the improper testimony here, while quite prejudicial, was not so
prejudicial that a mistrial was plainly the only acceptable remedy, even had the
defense requested it.
Lopez also raises two challenges to the court’s imposition of a fifty-year
prison sentence. First, he argues that the trial court erred in denying him sentencing
credit for time he spent incarcerated in El Salvador while awaiting extradition. This
argument, which Lopez raised below, hinges on facts that we have no findings on,
so we remand the case for the trial court to reconsider its sentence after making the
relevant and necessary findings. Second, he argues that his sentence may have
exceeded the maximum sentence permitted by “the extradition order from the
Supreme Court of El Salvador,” directing Lopez’s return to the United States to stand
trial. He has not fleshed that argument out enough to have any viable claim for relief,
as he cannot point us to any term in that extradition order that his sentence violates.
I. Background
Arrollo and Lopez started dating in 2012. That romantic relationship lasted
for a couple of years, though it was marked by turmoil and violence, and their 4
frequent fights led to police intervention on several occasions. Gricelda Rivera lived
with the couple and witnessed some of their fights. She explained that Lopez would
sometimes threaten to kill Arrollo and say, “[I]f she wasn’t going to be for him, then
she wasn’t going to be for anybody.”
After a tumultuous two-year relationship, Arrollo left Lopez at some point
around the beginning of December 2014. The record is not entirely clear about when
precisely they broke up, perhaps because—as these things sometimes go—the
breakup did not occur in one neat and tidy moment. But Arrollo moved out of their
shared apartment and in with a new boyfriend, Juan Campos, early in December
2014. Just before Arrollo moved out, Lopez told her that he had a gun and threatened
to kill her if she left him for somebody else. In the days after Arrollo moved in with
him, Campos overheard phone calls where Lopez threatened to kill Arrollo. Lopez
then posted a photo to Facebook on December 17—just a week ahead of the
murder—depicting more than two dozen rounds of ammunition arranged to spell
“Te Amo,” or I love you. Two boxes of ammunition were underneath that message,
with a hand-scrawled note: “Pero Si Me Fallas Todas Son Para Ti,” which translates
to “But if you fail me, all of them are for you.” 1
1 Many of the messages in this case were in Spanish and translated into English for trial. From here on, we will stick to the various messages’ English translations throughout this opinion. 5
The day after posting that to Facebook, Lopez sent Arrollo a direct message:
“Never in my life will I forgive you for this betrayal,” and he followed up with,
“Now you’ll know who I really am. You already know that you’re my life and you’re
in that dog’s house. But I’ll find you both ok.” Lopez then continued with a string
of threatening direct messages, saying, “Where it started it will end,” in an apparent
reference to Sabor Latino, where he first met Arrollo; “You’re going to die. I swear
it.”; “Remember this, I’m going to shoot you 4 times.” A few days later, now just
three days before Arrollo would be shot and killed, Lopez messaged Arrollo that he
was “over all the pain that [he] was feeling” and invited her to come back to the
apartment to retrieve her belongings, but she refused.
On December 24, 2014, Campos drove Arrollo to Sabor Latino, where she
worked as a waitress, for her 5 p.m. shift. Lopez’s roommate testified that he
abruptly left their shared apartment at around that same time. After Campos dropped
Arrollo off, and as Campos was driving away, he saw Lopez walking across 14th
Street toward the restaurant. Campos tried to send Arrollo a message warning her
that Lopez was in the area, but could not get a hold of her, and he did not see what
happened next. An eyewitness inside Sabor Latino recognized a man he had seen
with Arrollo “a few times” crossing 14th Street toward the restaurant. The witness
saw the man grab Arrollo as she struggled to open the door to the restaurant. The
witness and a nearby manager went to the door to let Arrollo in, but by the time they 6
got there she had fallen back and lost consciousness, and there was “a lot of blood
on the ground.” Two police officers who were about a block away heard the gunshots
and responded to the scene. One officer stayed with Arrollo and the other chased the
fleeing shooter down a side street, but the shooter got away.
After the shooting, Campos showed the police Lopez’s Facebook post with
the message written in rounds of ammunition. The police quickly zeroed in on Lopez
as the prime suspect, but they were unable to locate him. The government
nonetheless indicted Lopez in 2016, charging him with first-degree murder while
armed and possession of a firearm during a crime of violence. Lopez was eventually
arrested in El Salvador in 2020 or 2021, and El Salvador extradited him to the United
States in 2023 to stand trial. A jury found Lopez guilty of both counts based largely
on the evidence recounted above, though we will add some further details about
admitted expert testimony below.
Before sentencing, Lopez raised two claims that are relevant here. First, he
argued that he should be given credit for the two-plus years he was incarcerated
while awaiting extradition from El Salvador. Second, he argued that the extradition
order directing Lopez’s return to the United States might have placed some unknown
cap on his maximum sentence. Defense counsel had the relevant order in hand, but
he represented that it had not yet been translated and further indicated that he would 7
file a motion if the extradition agreement conflicted with the court’s ultimate
sentence.
The judge then sentenced Lopez to fifty years’ imprisonment. The judge gave
Lopez “credit for time served in the United States” but indicated (without stating any
reasons) that Lopez would not get any “credit for any time in El Salvador.” Defense
counsel objected that Lopez should be given credit for the entirety of his pre-trial
detention abroad, and without substantive refute, the court responded with “[i]f that
is an illegal sentence, let me know.” The judgment and commitment order that
followed expressly gave Lopez “credit for time served in the United States.” As for
Lopez’s second sentencing challenge, the judge indicated that he did not “know what
kind of agreement was worked out between the United States and El Salvador”
because “[n]obody’s filed anything” about that.
Lopez now appeals.
II. Analysis
We first address Lopez’s lone challenge to the guilt phase of his trial,
concerning the government expert’s testimony, and then we address his two
sentencing challenges. 8
A. The trial court did not plainly err in failing to sua sponte declare a mistrial
Lopez argues that the government’s domestic violence expert, Dr. Chitra
Raghavan, made two statements that were so prejudicial to his case that the trial
court was required to declare a mistrial sua sponte. Because the trial court failed to
take that required action, Lopez argues that we must now reverse his convictions.
Before we address the merits of that claim, we first detail Raghavan’s testimony.
Before trial, the government notified Lopez of its intent to introduce the
testimony of Raghavan as an expert in “traumatic bonding and coercive control in
the context of domestic violence.” The government argued that Raghavan’s
testimony would help explain “paradoxical, incongruous behavior by the victim [of
an abuser] that is often hard for a lay person, like a juror, to understand.” Raghavan
also proposed to explain how and “why a relationship may become more lethal”
when the victim “successfully ends the relationship with the abuser.” Lopez moved
to exclude this testimony on several grounds, including that it appeared to be rank
propensity evidence. That is, it appeared to invite jurors to infer from Lopez’s past
bad acts (domestic violence) that he had committed the charged murder. The trial
court agreed with defense counsel, in part, and permitted the expert to testify, but
not as to “the factors and circumstances which increase the likelihood an abuser will
kill or attempt to kill a victim.” 9
Raghavan nonetheless exceeded the court-ordered limitations on her
testimony on two occasions. First, she responded to one of the government’s
questions by indicating that the age difference between partners in a relationship
bore some relationship to the likelihood that the relationship would become deadly.
She began to explain what that relationship was, but she managed to get out only
“[W]hat it does . . .” before defense counsel objected. The government correctly
noted that Raghavan’s answer was not responsive to the question, and the court
sustained defense counsel’s objection. Defense counsel then indicated that he did
not want the court to “strik[e] anything” because he did not want “to call any
attention” to the improper but nascent testimony.
Second, and not long thereafter, Raghavan testified in a manner that far more
egregiously violated the limitations on her testimony. She was discussing a “myth”
that domestic violence ends when the relationship ends, and she explained that “[i]n
some relationships the coercion increases about a month before she leaves until
about a year after she leaves.” She then described a recent study in which “most of
the women . . . were murdered within a month to six months of leaving their
abusers.” Defense counsel objected and asked the court to strike the comment “with
an admonishment.” The trial court sustained the objection and told the jury “to strike
and not give any weight” to “the statement . . . that women were murdered within 10
one month to six months after leaving their abuser.” Defense counsel sought no
further remedy.
Lopez now argues that the above statements were so prejudicial that the trial
court erred in failing to sua sponte declare a mistrial that defense counsel never
requested. The government is correct that this claim was unpreserved, so that we
review it only for plain error: “When an appellant argues for a mistrial after having
failed to seek one in the trial court, we review the record only for plain error.”
McGriff v. United States, 705 A.2d 282, 288 (D.C. 1997); see also Lucas v. United
States, 20 A.3d 737, 744 (D.C. 2011) (similar); Lewis v. United States, 930 A.2d
1003, 1008 (D.C. 2007) (similar). 2 We discern no plain error for two principal
reasons.
First, when the government or one of its witnesses improperly injects
prejudicial testimony into the trial, we doubt it is ever plain error for the court not to
sua sponte declare a mistrial that the defendant has not requested. That is because it
is generally improper, under those circumstances, for the court to grant a mistrial
2 To prove plain error, an appellant must demonstrate (1) error, (2) that such error is “‘plain,’ meaning ‘clear’ or ‘obvious,’ by the time of appellate review”; (3) that the error affected their “substantial rights”; and (4) that the error “seriously affected ‘the fairness, integrity or public reputation of [the] judicial proceedings.’” Chew v. United States, 314 A.3d 80, 83 n.1 (D.C. 2024) (quoting In re Taylor, 73 A.3d 85, 96 (D.C. 2013)). 11
that the defendant does not want, and there are many good reasons why a defendant
may wish to see his trial through to its end, even with the injection of some improper
prejudice, rather than starting anew. See Walker v. United States, 317 A.3d 388, 408
(D.C. 2024) (“To simply start things over from scratch would be a sizable boon for
the government.”). “When mid-trial ‘prosecutorial error’ like the one here prejudices
a defendant, our precedents show an unflinching commitment to the principle that
the defendant must ‘retain primary control over the course to be followed.’” Id. at
392 (quoting Oregon v. Kennedy, 456 U.S. 667, 676 (1982)). And because Lopez
has not shown that he plainly would have acquiesced to a mistrial, despite defense
counsel’s failure to request one, his argument does not even get off the ground.
Second, even if we put that fatal flaw in his argument aside and assume for
the sake of argument that Lopez would have acquiesced to a mistrial, this testimony
was not so prejudicial that a mistrial was plainly the only proper remedy. The first
piece of Raghavan’s testimony said virtually nothing—she hinted that age
discrepancies between partners had some relationship to the likelihood that abuse
would turn deadly, but she never said or implied anything about what that
relationship was. And while it appears that Lopez was about eight years older than
Arrollo, that age difference was not highlighted in the testimony. It is also not clear
or obvious to us that jurors would have presupposed anything about what Raghavan 12
would have had to say, had she not been cut off, about how such modest age
differences might bear on a relationship turning deadly.
Lopez’s next challenge to Raghavan’s testimony has far more merit to it.
Raghavan’s testimony that “most of the women” in one study “were murdered within
a month to six months of leaving their abusers” was far more prejudicial, as it
mapped onto the facts of this case. That testimony clearly invited the jury to draw
an impermissible propensity inference—that because abusers tend to kill their
partners shortly after their relationship ends, and because Lopez was abusive in their
relationship which had previously ended, it stood to reason that he killed her. See In
re Richardson, 273 A.3d 342, 350 (D.C. 2022) (“It is fundamental that evidence of
prior bad acts independent of the crimes charged is inadmissible to show the
defendant’s disposition or propensity to commit the charged offenses.” (quoting
Harrison v. United States, 30 A.3d 169, 176 (D.C. 2011))); see also Fed. R. Evid.
404(b)(1). But as prejudicial as this testimony was, it is neither clear nor obvious
that a mistrial was the only potentially effective remedy. “Our caselaw abounds with
similar cases where curative instructions were found to have sufficiently mitigated
extremely damning evidence introduced against a defendant.” Walker, 317 A.3d at
412 & n.17 (collecting cases). Plus, the fact that Lopez did not ask for a mistrial and
instead asked only that the testimony be stricken is itself strong evidence that a
mistrial was not required here. See Hunter v. United States, 606 A.2d 139, 145 (D.C. 13
1992) (“The lack of any reaction from defense counsel might have suggested that
she did not perceive any prejudice, a fact which is itself suggestive in some measure
of lack of prejudice.”). In our view, the trial court “could thus reasonably [have]
conclude[d], in the absence of a defense objection, that the situation was not extreme
enough to warrant [an] uninvited” mistrial. See id. at 146.
Finally, we note the government’s case against Lopez was incredibly strong
relative to the prejudicial impact of Raghavan’s improper comments. See Young v.
United States, 305 A.3d 402, 418 (D.C. 2023) (considering “the relative strength of
the government’s case” when assessing the necessity for a mistrial (quoting Trotter
v. United States, 121 A.3d 40, 53 (D.C. 2015))). The government presented
testimony from several eyewitnesses to the shooting, including one (Campos) who
positively identified Lopez walking toward Arrollo just before she was killed, and it
introduced messages from Lopez threatening to kill Arrollo multiple times in the
days before she was killed. And then there is the further incriminating fact that Lopez
promptly fled the country after Arrollo was killed. In light of the government’s very
strong case, Raghavan’s challenged comments, prejudicial though they may have
been, stood little chance of having swayed the jury to convict if the remainder of the
evidence had not already done the trick. On this record, we conclude the trial court
did not plainly err by failing to sua sponte declare a mistrial, so we affirm Lopez’s
convictions. 14
B. Sentencing issues
Lopez next raises two sentencing challenges. First, he argues that the trial
court erred when, without explanation, it denied him credit for time served while
awaiting extradition in El Salvador. Second, he argues that a remand is required “to
allow argument on whether the extradition order from the Supreme Court of El
Salvador prohibited [the trial judge] from imposing the fifty-year sentence.”
As to Lopez’s first claim, we remand for resentencing. The trial court never
explained why it denied Lopez credit for time he spent incarcerated in El Salvador,
and he raised a potent argument that he was entitled to credit for that time served.
See D.C. Code § 24-221.03(a) (“Every person shall be given credit on the maximum
and the minimum term of imprisonment for time spent in custody . . . as a result of
the offense for which the sentence was imposed.”). The government now seems to
agree with Lopez that he was entitled to credit for that time served, at least insofar
as he was being held in El Salvador “solely” on account of his pending extradition
(as opposed to serving time on some other charge). The government nonetheless
argues that we should not review this claim because Lopez did not provide
“documentation to support his claim” before the trial court, so that his only remedies
now would be to petition the Bureau of Prisons, or BOP, or to seek a writ of habeas
corpus. 15
We disagree with the government. The trial court did not suggest that Lopez’s
claim lacked sufficient documentation—if it had, Lopez might have readily supplied
it. The court instead rejected this claim for untold reasons that it should explain or
reconsider on remand. When the record is “not clear” about a material disputed fact
“which was not squarely presented to or relied upon by the trial court” in a
sentencing credit decision, and the parties do not otherwise dispute the applicable
law, we may remand to the sentencing court to clarify any findings. See Ali v. District
of Columbia, 612 A.2d 228, 230 (D.C. 1992). And contrary to the government’s
argument, Lopez would not seem to have any effective remedy within BOP because
the trial judge here expressly declined to give Lopez credit for the time he spent
incarcerated in El Salvador, and BOP has no authority to second guess that judicial
judgment call. It is the court’s province to impose and announce the sentence to be
served, and the BOP is left to execute and administer that sentence—it is not free to
rewrite it. See generally Alston v. United States, 590 A.2d 511, 514 (D.C. 1991)
(explaining that “imposition of [the] sentence” is left to the trial court, whereas
“execution of [the] sentence” is left to the “executive department,” typically BOP);
Francis v. United States, 715 A.2d 894, 898 n.9 (D.C. 1998) (explaining that the
“judiciary . . . pronounce[s the] sentence,” and “the executive . . . administers it”).
While a petition for a writ of habeas corpus might present an alternative route for 16
relief, see Alston, 590 A.2d at 514, the availability of that route does not obviate
Lopez’s right to a reasoned decision from the sentencing court itself.
As to Lopez’s second claim, we discern no grounds for a remand because
Lopez has not made so much as a bare representation that his sentence violates any
term of the extradition order. Lopez and his counsel are in possession of that
extradition order, and have all the tools necessary to translate it, evaluate what it
says, and make some representation or argument about how the fifty-year sentence
imposed here violates it. And yet, neither before the trial court nor before this court
has Lopez actually been able to point to any term in the extradition order that his
sentence violates. We are not in the habit of remanding cases for parties to consider
fleshing out claims that they have to date been unable to articulate, as that would be
an extraordinary waste of finite court resources. We do not foreclose the possibility
that Lopez might be entitled to some collateral relief on this claim if he comes
forward with persuasive evidence that his sentence does in fact violate the terms of
his extradition. But on this record, where Lopez seems to have all the tools at his
disposal to flesh out any argument that his sentence violates the extradition order
and yet has never actually articulated a concrete argument to that effect, we see no
basis to direct the trial court to consider his claim. 17
III. Conclusion
For the foregoing reasons, we affirm Lopez’s convictions and remand the case
to the trial court to reconsider, or to further explain, its decision declining to give
Lopez credit for the time he spent incarcerated while awaiting extradition.
So ordered.