IN THE UNITED STATES COURT OF APPEALS

FOR THE FIFTH CIRCUIT

No. 17-10746

UNITED STATES OF AMERICA, 

 Plaintiff - Appellee

v.

MARTAVIOUS DETREL BANKS KEYS, also known as Cheese, also known 

as Matt, 

 Defendant - Appellant

Appeal from the United States District Court 

for the Northern District of Texas

USDC No. 3:16-CR-244-1

Before CLEMENT, HIGGINSON, and HO, Circuit Judges.*

PER CURIAM:*

Martavious Detrel Banks Keys was convicted by a jury of two counts of 

sex trafficking of a child and one count of sex trafficking through force, fraud, 

or coercion in violation of 18 U.S.C. § 1591. Keys appeals, contending that 

Count One and Count Three of the indictment were multiplicitous and that the 

 

* Judge Ho concurs in the judgment only. 

** Pursuant to 5TH CIR. R. 47.5, the court has determined that this opinion should not 

be published and is not precedent except under the limited circumstances set forth in 5TH 

CIR. R. 47.5.4.

United States Court of Appeals

Fifth Circuit

FILED

August 20, 2018

Lyle W. Cayce

Clerk

 Case: 17-10746 Document: 00514606524 Page: 1 Date Filed: 08/20/2018
No. 17-10746

2

district court erred in admitting the testimony of two law enforcement officers. 

For the reasons stated below, we AFFIRM.

I

On March 13, 2015, Jane Doe 1 and Jane Doe 2 left the Nexus Recovery 

Center, a substance abuse treatment facility in Dallas, Texas. The girls were 

15 years old and 14 years old, respectively. At a gas station they reached on 

foot, Jane Does 1 and 2 met an adult male they identified as “Black,” who 

offered to take them back to his apartment and provide them with narcotics. 

Jane Doe 1 told Black that the girls were both 15 years old. The girls stayed at 

Black’s apartment for approximately three days. During that time, Black and 

another man provided Jane Does 1 and 2 with methamphetamine and crack 

cocaine, and the girls engaged in sex acts with the two men. While staying at 

Black’s apartment, Jane Does 1 and 2 also met another friend of Black’s, later 

identified as Keys or “Cheese.” Black later drove the girls to an abandoned area 

and sold them to Keys.1

Keys took the girls back to his apartment, where he created a 

Backpage.com2 ad inviting potential patrons to engage in commercial sex with 

an apparently fictional individual named “Kacy.” Using a number of prepaid 

cell phones, Keys arranged for men to come to his apartment to engage in sex 

acts with the girls in exchange for money. When the men would arrive at Keys’s 

apartment, Jane Doe 1 would greet them at the door and lead them to a 

bedroom where she would instruct them to choose between herself and Jane 

Doe 2. Both girls would be naked. After the men chose Jane Doe 1, Jane Doe 2, 

 

1 Jane Doe 1 told investigators that Keys purchased Jane Doe 1 for $240 and Jane Doe 

2 for $47.

2 Backpage.com “is Craigslist for the sex trade.” In 2018, Backpage.com pleaded guilty 

to human trafficking in Texas. See 

https://www.texasattorneygeneral.gov/news/releases/backpage.com-pleads-guilty-to-humantrafficking-in-texas. 

 Case: 17-10746 Document: 00514606524 Page: 2 Date Filed: 08/20/2018
No. 17-10746

3

or both girls, Jane Doe 1 would collect the cash and pass it under the bathroom 

door to Keys, who would be waiting on the kitchen side. Jane Doe 2 estimates 

that she engaged in commercial sex acts roughly ten times total while at Keys’s 

home. Jane Doe 1 testified that, on average, she engaged in commercial sex 

acts sixteen times per day. On at least one occasion, her vagina was so swollen 

and bleeding that Keys suggested she insert cosmetic sponges inside herself 

or, alternatively, have anal sex so that she could continue to entertain 

customers. Keys kept all of the money the girls earned. 

At some point, Jane Doe 1 and Jane Doe 2 told Keys that they were only 

15 and 14 years old. He continued to have the girls engage in commercial sex 

acts with men. Keys also raped Jane Doe 1 on multiple occasions and Jane Doe 

2 at least once. While both girls were still at his home, Keys left for several 

days, apparently to pick up a Chevrolet Tahoe he was able to purchase with 

the money earned by the girls. His friends monitored the girls while he was 

gone. Keys and his friends provided Jane Does 1 and 2 with a constant supply 

of crack cocaine. Though Jane Doe 2 initially wanted to use drugs, she 

eventually became uncomfortable and wanted to stop and “get out of there.”

Keys and Jane Doe 1 pressed her to continue using, and Keys became violent. 

Jane Doe 2 testified that when she told Keys she no longer wanted to engage 

in commercial sex acts, Keys choked her, slammed her against the wall and 

said: “If you don’t do what you’re supposed to do, we’re going to have a 

problem.”

Jane Doe 2 was able to leave Keys’s apartment approximately two weeks 

after he purchased her from Black. After Keys threatened her, Jane Doe 2 

asked the next customer who came to the apartment if he would help her get 

out. The customer apparently paid Keys to let him leave with Jane Doe 2. Jane 

Doe 1 remained with Keys for roughly two weeks after Jane Doe 2 left, during 

which time Keys began shuttling her between various motels. She continued 

 Case: 17-10746 Document: 00514606524 Page: 3 Date Filed: 08/20/2018
No. 17-10746

4

to engage in sex acts with various customers and Keys collected the money. 

But the character of the relationship between Keys and Jane Doe 1 shifted. 

Keys became more violent and controlling. Keys regularly abused Jane Doe 1 

and pointed a gun at her; she testified that she did not feel free to leave. Jane 

Doe began to fear for her life. She believed, however, that if she ran away, Keys 

would come after her. At one point, Keys posted an ad offering commercial sex 

to customers in Houston on Backpage.com and drove Jane Doe 1 there in his 

Tahoe. The trip was cut short when Keys got into a physical altercation with a 

friend and beat him severely.

Though Jane Doe 1 was afraid Keys would find her if she attempted to 

leave him, an older prostitute ultimately convinced her that leaving Keys was 

the safest choice. The woman took Jane Doe 1 to another apartment. Keys 

showed up less than a day later with three friends and a gun, which he pointed 

in Jane Doe 1’s face. A man staying at the apartment with Jane Doe 1 and the 

older prostitute came out with a large gun and forced the men to leave without 

Jane Doe 1. For the next week, she could not leave the house alone because 

Keys had friends patrolling the street. Jane Doe 1 was recovered by the police 

roughly one week later, on May 4, 2015. She was severely sleep-deprived, 

malnourished, and suffering from sexually transmitted diseases. 

On May 5, officers executed a search warrant of Keys’s residence. Among 

other items, officers retrieved a semiautomatic pistol, sex toys, a laptop, and 

multiple cell phones. The officers interviewed Jane Does 1 and 2 extensively, 

and they were able to locate several Backpage.com ads posted by Keys that fit 

the description provided by Jane Doe 1. Records subpoenaed by law 

enforcement from motels identified by Jane Doe 1 confirmed that Keys had 

paid for several rooms during the relevant time frame. In May 2015, Detective 

Kevin Halbert called Keys for an interview, and Keys initially agreed to meet. 

Keys did not show up for the meeting, and law enforcement spent the next year 

 Case: 17-10746 Document: 00514606524 Page: 4 Date Filed: 08/20/2018
No. 17-10746

5

attempting to locate him. Halbert interviewed Keys in person for the first time 

in May 2016. Keys admitted to Halbert that he knew the girls, that they had 

stayed with him for a period of time, that they engaged in prostitution, and 

that he discovered at some point that they were underage. He claimed that 

when he found out Jane Does 1 and 2 were only 15 and 14 years old, he had 

them leave his apartment. Keys also admitted that he had set up the 

Backpage.com ads. Keys maintained, however, that he was a passive observer 

and was simply “trying to take care of [the girls]”—he denied that he facilitated 

their engagement in commercial sex. At first, Keys denied taking any money 

from the girls; eventually, he admitted that he accepted money from them, 

though he claimed it was only so that he could feed and house them.

Keys was ultimately indicted on three counts of sex trafficking. Count

One charged Keys with sex trafficking of children under 18 U.S.C. § 1591(a) 

and (b)(2) for causing Jane Doe 1, who was under 18 years of age, to engage in 

commercial sex acts. Count Two charged Keys with sex trafficking of children 

under § 1591(a) and (b)(2) for causing Jane Doe 2, also a minor, to engage in 

commercial sex acts. Count Three charged Keys with sex trafficking Jane Doe 

1 through force, fraud, or coercion under § 1591(a)(1) and (b)(1)–(2).

Prior to trial, the defense filed a motion to dismiss Count One to avoid 

multiplicity, arguing that Counts One and Three punish the same criminal 

offense in violation of the Double Jeopardy Clause. The district court carried 

the motion with the case, and ultimately submitted all three counts to the jury. 

Several law enforcement witnesses testified, including Halbert and Special 

Agent Phillip Campbell, who explained how the hotel, cell phone, 

Backpage.com ads, and social media records obtained during the investigation 

corroborated the girls’ account of their experience. Both law enforcement 

officers testified that they believed Keys had a reasonable opportunity to 

 Case: 17-10746 Document: 00514606524 Page: 5 Date Filed: 08/20/2018
No. 17-10746

6

observe the girls and that he caused or compelled them to engage in 

commercial sex acts. The defense did not object to the testimony at trial. 

Keys was found guilty of all three sex trafficking counts. The district 

court sentenced Keys according to the applicable guideline range to life in 

prison and imposed a mandatory special assessment of $300.00. Keys did not 

reassert his multiplicity objection at sentencing, though the defense did object 

that Presentence Report applied numerous, overlapping enhancements and 

resulted in Keys being “punished over and over again for the same conduct and 

the same idea.” Keys appeals and presents two issues for review: 1) whether 

the district court erred in denying Keys’s motion to dismiss Count One for 

multiplicity; and 2) whether the district court plainly erred in allowing Halbert 

and Campbell’s testimony at trial. Specifically, Keys contends that Halbert and 

Campbell improperly opined that Keys was guilty of the offenses charged and 

that he was lying during his interview when he denied direct involvement in 

the crime.

II

This court reviews issues of multiplicity de novo. United States v. Dupre, 

117 F.3d 810, 818 (5th Cir. 1997). 

Because Keys did not object to the officers’ testimony at trial, this court 

reviews the district court’s admission of that testimony only for plain error. 

United States v. Garcia-Flores, 246 F.3d 451, 457 (5th Cir. 2001). Under plain 

error review, the court may remedy the alleged error only if: (1) there is an 

error or defect; (2) the error is clear or obvious; and (3) the error affected the 

appellant’s substantial rights. See Puckett v. United States, 556 U.S. 129, 135 

(2009). “An error is plain if it is at least clear under current law.” United States 

v. Gonzalez-Rodriguez, 621 F.3d 354, 363 (5th Cir. 2010) (internal quotations 

omitted). The error must be “so clear or obvious that the trial judge and 

prosecutor were derelict in countenancing it, even absent the defendant’s 

 Case: 17-10746 Document: 00514606524 Page: 6 Date Filed: 08/20/2018
No. 17-10746

7

timely assistance in detecting it.” United States v. Trejo, 610 F.3d 308, 319 (5th 

Cir. 2010) (internal quotations omitted). For the error to have affected the 

appellant’s substantial rights, “the error must have been prejudicial,” meaning 

that “[i]t must have affected the outcome of the district court proceedings.” 

United States v. Olano, 507 U.S. 725, 734 (1993). To demonstrate prejudice, “a 

defendant must show a reasonable probability that, but for [the error claimed], 

the result of the proceeding would have been different.” United States v. 

Holmes, 406 F.3d 337, 365 (5th Cir. 2005) (alteration in original) (internal 

quotations omitted). In regards to potentially improper witness testimony, this 

court has stated: “[E]ven if we were to find the existence of plain error, we could 

find it harmless if there is sufficient evidence, aside from any potentially 

impermissible testimony, from which the jury could find the Defendant[] 

guilty.” United States v. Espino-Rangel, 500 F.3d 398, 400 (5th Cir. 2007). “[I]f

the above three prongs are satisfied, the court of appeals has the discretion to 

remedy the error—discretion which ought to be exercised only if the error 

seriously affect[s] the fairness, integrity, or public reputation of judicial 

proceedings.” Puckett, 556 U.S. at 135 (alteration in original) (internal 

quotations omitted). 

III

Keys first contends that Count One and Count Three of the indictment 

are multiplicitous because they charge him twice for trafficking the same 

person—Jane Doe 1.

The relevant criminal statute reads:

(a) Whoever knowingly–

(1) in or affecting interstate or foreign commerce, or within 

the special maritime and territorial jurisdiction of the United 

States, recruits, entices, harbors, transports, provides, obtains, 

advertises, maintains, patronizes, or solicits by any means a 

person; or

 Case: 17-10746 Document: 00514606524 Page: 7 Date Filed: 08/20/2018
No. 17-10746

8

(2) benefits, financially or by receiving anything of value, 

from participation in a venture which has engaged in an act 

described in violation of paragraph (1),

knowing, or . . . in reckless disregard of the fact, that means of 

force, threats of force, fraud, coercion described in subsection (e)(2), or 

any combination of such means will be used to cause the person to engage 

in a commercial sex act, or that the person has not attained the age of 18 

years and will be caused to engage in a commercial sex act, shall be 

punished as provided in subsection (b).

18 U.S.C. § 1591(a). Subsection (b) prescribes different mandatory minimum 

sentences for sex trafficking of a child between the ages of fourteen and 

eighteen, sex trafficking of a child under age 14, or sex trafficking by force:

(b) The punishment for an offense under subsection (a) is–

(1) if the offense was effected by means of force, threats of 

force, fraud, or coercion described in subsection (e)(2), or by any 

combination of such means, or if the person recruited, enticed, 

harbored, transported, provided, obtained, advertised, patronized, 

or solicited had not attained the age of 14 years at the time of such 

offense, by a fine under this title and imprisonment for any term 

of years not less than 15 or for life; or

(2) if the offense was not so effected, and the person 

recruited, enticed, harbored, transported, provided, obtained, 

advertised, patronized, or solicited had attained the age of 14 years 

but had not attained the age of 18 years at the time of such offense, 

by a fine under this title and imprisonment for not less than 10 

years or for life.

18 U.S.C. § 1591(b). Subsection (c) provides that in a prosecution for trafficking 

any individual under eighteen, if “the defendant had a reasonable opportunity 

to observe” the victim, “the Government need not prove that the defendant 

knew, or recklessly disregarded the fact, that the person had not attained the 

age of 18 years.” 18 U.S.C. § 1591(c).

 Case: 17-10746 Document: 00514606524 Page: 8 Date Filed: 08/20/2018
No. 17-10746

9

The government charged Keys with two separate counts of sex 

trafficking Jane Doe 1 under the statute: Count One) a violation of 18 U.S.C. § 

1591(a)(1) and (b)(2) by causing Jane Doe 1, who was under 18 years of age, to 

engage in commercial sex acts; and Count Three) a violation § 1591(a)(1) and 

(b)(1) for sex trafficking Jane Doe 1 through force, fraud, or coercion. The 

government maintains that Subsections (b)(1) and (b)(2) enumerate two 

separate crimes which contain different elements, proof requirements for 

intent, and penalties. Further, the government argues that, even if (b)(1) and 

(b)(2) are not separate crimes, Keys committed two distinct prohibited acts

during the relevant time period. Keys contends that Subsection (a)(1) 

enumerates only one crime that can be committed in one of two ways: causing 

an individual to engage in a commercial sex act through force, fraud, or 

coercion or causing an individual under eighteen years of age to engage in a 

commercial sex act. He asserts that because Count One and Count Three are

predicated on a single, continuous course of criminal conduct involving the 

same victim, the government cannot charge both simultaneously. 

Indictments are multiplicitous if they charge a single offense in two or 

more separate counts. United States v. Ogba, 526 F.3d 214, 232–33 (5th Cir. 

2008). Such indictments implicate, for obvious reasons, Double Jeopardy 

concerns. United States v. Sanjar, 876 F.3d 725, 737 (5th Cir. 2017), cert. 

denied sub nom. Main v. United States, No. 17-8107, 2018 WL 1317751 (U.S. 

Apr. 16, 2018). They punish the defendant twice for the same conduct “where 

Congress has not authorized cumulative punishment.” See Ogba, 526 F.3d at 

232–33. “The chief danger raised by a multiplicitous indictment is the 

possibility that the defendant will receive more than one sentence for a single 

offense.” United States v. Swaim, 757 F.2d 1530, 1537 (5th Cir. 1985). At 

bottom, the multiplicity inquiry is a question of statutory construction—

 Case: 17-10746 Document: 00514606524 Page: 9 Date Filed: 08/20/2018
No. 17-10746

10

whether Congress intended to permit cumulative punishment for one instance 

or pattern of conduct. See Ogba, 526 F.3d at 232–33.

This court applies the test laid out in Blockburger v. United States, 284 

U.S. 299 (1932) to discern whether Congress has prescribed multiple 

punishments for the same conduct. See Ogba, 526 F.3d at 233; See United 

States v. Davis, 656 F.2d 153, 156 n.1 (1981) (citing United States v. Goodman, 

605 F.2d 870 (5th Cir. 1979)); Normandale v. United States, 201 F.2d 463 (5th 

Cir.), cert. denied 345 U.S. 999 (1953)). “The applicable rule is that where the 

same act or transaction constitutes a violation of two distinct statutory 

provisions, the test to be applied to determine whether there are two offenses 

or only one is whether each provision requires proof of a fact which the other 

does not.” United States v. Nguyen, 28 F.3d 477, 485 (5th Cir. 1994) (citing 

Albernaz v. United States, 450 U.S. 333, 336–38 (1981); see also Blockburger, 

284 U.S. at 304; Davis, 656 F.2d at 156 n.1 (noting that Blockburger “applie[s] 

to several offenses enumerated in one statutory section as well as to offenses 

named in separate sections”). As long as each statutory provision requires 

proof of a fact the other does not, “the Blockburger test is satisfied, 

notwithstanding a substantial overlap in the proof offered to establish the 

crimes.” Nguyen, 28 F.3d at 485 (quoting Brown v. Ohio, 432 U.S. 161, 166 

(1977)).

Keys’s indictment passes muster under Blockburger. Count One and 

Count Three charge Keys under two separate subsections of 18 U.S.C. § 1591—

subsections (b)(1) and (b)(2). Each subsection requires proof of a fact that the 

other subsection does not. Subsection (b)(1) requires the government to prove 

that the defendant knew or recklessly disregarded the fact that the offense 

would be effected by means of force, fraud, or coercion. See 18 U.S.C. 1591(b)(1). 

Trafficking by force can be charged irrespective of the victim’s age. Subsection 

(b)(2) requires that the government prove that the defendant knew or 

 Case: 17-10746 Document: 00514606524 Page: 10 Date Filed: 08/20/2018
No. 17-10746

11

recklessly disregarded the fact that the victim was under 18 years old. 18 

U.S.C. § 1591(b)(2). Moreover, under subsection (b)(2), the government can 

satisfy the intent requirement by demonstrating that the defendant had a 

reasonable opportunity to observe the victim—it need not demonstrate that 

the defendant actually knew or recklessly disregarded her age. See 18 U.S.C. 

§ 1591(c). In other words, subsection (c) imposes strict liability on defendants 

regarding a victim’s age. United States v. Copeland, 820 F.3d 809, 813 (5th Cir. 

2016). Subsection (c) does not so alter the intent requirement for force under 

subsection (b)(1). See 18 U.S.C. § 1591(c).3 In sum, the subsections require the 

government to prove different elements, each of which requires different 

evidence. Despite the fact that Keys engaged in a single, continuous course of 

unbroken criminal conduct, he can properly be charged separately with 

violating both statutory subsections.

When assessing two subsections within a single statutory scheme, 

however, courts are generally more reluctant to rely on Blockburger alone to 

allow punishment under both provisions. See United States v. McLaughlin, 164 

F.3d 1, 15 (D.C. Cir. 1998); cf. United States v. Munoz-Romo, 989 F.2d 757, 759 

(5th Cir. 1993). Accordingly, it is often helpful to examine other indicia of 

congressional intent. For example, the fact that Congress has prescribed 

different penalties for violations of subsections (b)(1) and (b)(2)—a minimum 

of 10 years’ imprisonment for a violation of subsection (b)(2) and a minimum 

of 15 years for a violation of subsection (b)(1)—is a strong indication that it 

intended to allow for multiple punishments. See, e.g., United States v. 

Winchester, 916 F.2d 601, 605–08 (11th Cir. 1990) (holding multiple 

convictions under § 922(g) multiplicitous because, among other things, the 

 

3 Subsection (c) would apply to a charge under subsection (b)(1) for trafficking a victim 

under the age of 14. See 18 U.S.C. § 1591(c); Copeland, 820 F.3d at 813.

 Case: 17-10746 Document: 00514606524 Page: 11 Date Filed: 08/20/2018
No. 17-10746

12

statute “did not list separate penalties for the separate subdivisions of 

subsection (g)”).

Moreover, the legislative history indicates that Congress sought to 

punish trafficking aggressively. It has amended Section 1591 several times to 

allow more extensive prosecution of exploitative crimes. See Pub. L. No. 110-

457, 122 Stat. 5044 (2008); Pub. L. No. 114-22, 129 Stat. 247 (2015). The 

legislative record accompanying the Trafficking Victims Protection Act of 2000, 

which encompasses Section 1591, states that human trafficking is a “degrading 

institution of slavery” and “an evil requiring concerted and vigorous action.” 

Pub. L. No. 106-386, 114 Stat. 1464, Sec. 102(b)(1), 21 (2000). In short, the 

history of the statute supports construing subsections (b)(1) and (b)(2) as 

distinct crimes that can be charged separately.

Counts One and Three of Keys’s indictment are not multiplicitous. 

Accordingly, we AFFIRM Keys’s convictions on all three Counts.4

IV

We now turn to Keys’s challenge to the admissibility of law enforcement 

testimony. Keys alleges two overarching problems with Halbert and 

Campbell’s testimony. First, Keys contends that both officers improperly 

opined that Keys was guilty of the offenses charged. Second, Keys claims that 

Halbert was erroneously allowed to offer his opinion that Keys was not telling 

the truth during his police interview.

Both Halbert and Campbell testified as lay witnesses—neither was 

qualified as an expert. Accordingly, Federal Rules of Evidence 701 and 704(a) 

 

4 We note that each individual violation of Section 1591 charged in the indictment 

allows for a life sentence. See 18 U.S.C.§ 1591(b)(1), (2). At sentencing, the district court 

stated: “I’m going to sentence at the Guideline range and sentence the Defendant to life in 

prison. That sentence is on each of Counts 1, 2, and 3 to run concurrently.” This language 

indicates that the district court would have sentenced Keys to life in prison on any one of the 

charges. All of the conduct would still be relevant to the Guidelines computation in the PSR. 

 Case: 17-10746 Document: 00514606524 Page: 12 Date Filed: 08/20/2018
No. 17-10746

13

govern the propriety of their opinion testimony. FED R. EVID. 701, 704(a). Rule 

701 provides that non-expert opinion testimony must be: “(a) rationally based 

on the witness’s perception; (b) helpful to clearly understanding the witness’s 

testimony or to determining a fact in issue; and (c) not based on scientific, 

technical, or other specialized knowledge within the scope of Rule 702.” FED R.

EVID. 701. Rule 704 clarifies that “[a]n opinion is not objectionable just because 

it embraces an ultimate issue.” FED R. EVID. 704(a); see also Espino-Rangel, 

500 F.3d at 400 (stating that while lay witnesses may not offer legal 

conclusions, “testimony in the form of an opinion or inference otherwise 

admissible is not objectionable simply because it embraces an ultimate fact 

issue to be determined by the factfinder”).5 Rule 704 was, however, intended 

to preserve the effect of other evidentiary provisions meant to “assur[e] against 

the admission of opinions which would merely tell the jury what result to 

reach.” FED R. EVID. 704 advisory committee’s note to 1972 proposed rules. 

Thus, under Rule 704(a), testimony that amounts to a legal conclusion is 

improper. See United States v. Williams, 343 F.3d 423, 435 (5th Cir. 2003); see 

also United States v. McGee, 821 F.3d 644, 648–49 (5th Cir.), cert denied, 137 

S.Ct. 251 (2016).6 In evaluating challenged testimony, the court must 

 

5 Keys cites Rule 704(b) for the proposition that “an expert witness must not state an 

opinion about whether the defendant did or did not have a mental state or condition that 

constitutes an element of the crime charged or of a defense. Those matters are for the trier of 

fact alone.” “[B]ut neither [Halbert] nor [Campbell] was called as an expert witness, so FRE 

704(b) has no application in the instant case.” Espino-Rangel, 500 F.3d at 400. Moreover, 

“[l]ay witnesses [] may give opinion testimony about a defendant’s mental state.” United 

States v. Diaz, 637 F.3d 592, 599 (5th Cir. 2011); see also United States v. Heard, 709 F.3d 

413, 422 (5th Cir. 2013). 

6 Rule 704(a) is the source of the general limitation on opinion testimony on ultimate 

legal issues. See, e.g., McGee, 821 F.3d at 649; United States v. Izydore, 167 F.3d 213, 218 

(5th Cir. 1999); Owen v. Kerr-McGee Corp., 698 F.2d 236, 240 (5th Cir. 1983). This limitation 

applies equally to both lay witness and expert witness testimony. Compare Izydore, 167 F.3d 

at 218 and Williams, 343 F.3d at 435 (discussing the limitation when evaluating lay witness 

testimony) with United States v. Buchanan, 70 F.3d 818, 833 n.20 (5th Cir. 1995) and United 

 Case: 17-10746 Document: 00514606524 Page: 13 Date Filed: 08/20/2018
No. 17-10746

14

distinguish “between an impermissible opinion on an ultimate legal issue and 

‘a mere explanation of the [witness’s] analysis of facts which would tend to 

support a jury finding on the ultimate issue.’” United States v. Buchanan, 70 

F.3d 818, 833 n.20 (5th Cir. 1995) (quoting United States v. Speer, 30 F.3d 605, 

610 (5th Cir. 1994)).

Again, the defense did not object to the admission of the testimony at 

trial and therefore we review only for plain error. Garcia-Flores, 246 F.3d at 

457.

1. Opinion testimony relevant to Keys’s ultimate guilt

As this court has explained, “determinations of guilt or innocence are 

solely within the province of the trier of fact.” United States v. Izydore, 167 F.3d 

213, 218 (5th Cir. 1999); see also United States v. Buchanan, 70 F.3d 818, 833 

n.20 (5th Cir. 1995). Accordingly, a lay witness’s opinion that a defendant is 

guilty of the crime charged would be improper trial testimony. See id.; see also 

United States v. Thomas, 847 F. 3d 193, 206 (5th Cir. 2017). 

Relatedly, “questions which would merely allow the witness to tell the 

jury what result to reach are not permitted.” Owen v. Kerr-McGee Corp., 698 

F.2d 236, 240 (5th Cir. 1983). Of course, “separating impermissible questions 

which call for overbroad or legal responses from permissible questions is not a 

facile [task].” Id. The Advisory Committee Notes to the Federal Rules of 

Evidence offer the following example: While the question (1) “Did T have 

capacity to make a will?” would be improper, the question (2) “Did T have 

sufficient mental capacity to know the nature and extent of his property and 

the natural objects of his bounty and to formulate a rational scheme of 

 

States v. Speer, 30 F.3d 605, 610 (5th Cir. 1994) (discussing the limitation when evaluating 

expert witness testimony).

 Case: 17-10746 Document: 00514606524 Page: 14 Date Filed: 08/20/2018
No. 17-10746

15

distribution?” would be allowed. FED R. EVID. 704 advisory committee’s note to 

1972 proposed rules.

Attempting to shed light on why the first formulation is problematic, this 

court explained that it “is phrased in such broad terms that it could as readily 

elicit a legal as well as a fact based response. A direct response, whether it be 

negative or affirmative, would supply the jury with no information other than 

the [witness’s] view of how its verdict should read.” Owen, 698 F.2d at 240. The 

second formulation is permissible because it is not explicitly framed as a 

request for an opinion “phrased in terms of inadequately explored legal 

criteria.” FED R. EVID. 704 advisory committee’s note to 1972 proposed rules. 

Rather, it breaks down the question of testamentary capacity—a question that 

has a specific legal meaning—into its discrete elements. See 1 McCormic On 

Evid. §12 (7th ed.). Stated differently, questions (1) and (2) capture the 

distinction “between an impermissible opinion on an ultimate legal issue and 

‘a mere explanation of the [witness’s] analysis of facts which would tend to 

support a jury finding on the ultimate issue.’” Buchanan, 70 F.3d at 833 n.20 

(quoting Speer, 30 F.3d at 610).

Halbert engaged in the following exchanges with the prosecutor at trial: 

1) when asked, “[b]ased on all the information that you learned during your 

investigation, the entirety of it, did you believe that Jane Doe 1 had been 

compelled to engage in commercial sex acts through force, fraud, or coercion?” 

he responded, “[a]bsolutely”; 2) when asked “did you believe that the 

defendant, based on your investigation, had an opportunity to observe these 

girls?” he responded, “[a]bsolutely”; 3) when asked “did you believe, based on 

your investigation, that Jane Doe 2, being 14 at the time, was compelled to 

engage in commercial sex acts?” he responded, “[s]he was”; and 4) when asked 

“who do you believe compelled them to engage in those commercial sex acts?” 

he responded “[t]he defendant, Mr. Keys.”

 Case: 17-10746 Document: 00514606524 Page: 15 Date Filed: 08/20/2018
No. 17-10746

16

Similarly, Campbell had the following exchange with the prosecutor: 1) 

when asked, “[b]ased on your investigation in this case, do you believe that the 

defendant . . . caused Jane Doe 1 and Jane Doe 2 to engage in commercial sex 

acts in the Northern District of Texas?” he responded “I do”; 2) when asked “do 

you believe that the defendant either knew or had a reasonable opportunity to 

observe Jane Doe 1 and Jane Doe 2 during that time period?” he responded “I 

believe he did”; and 3) when asked “[d]o you believe that the defendant caused 

Jane Doe 1 to engage in commercial sex acts by force, fraud, or coercion?” he 

responded “[a]bsolutely.” 

The district court did not plainly err in admitting the above testimony. 

The formulations of the questions closely track the language of individual 

elements of the charged sex trafficking counts. See 18 U.S.C. § 1591(a), (c). For 

example, Counts One and Two required the government to prove that Keys: 1) 

knowingly recruited, enticed, harbored, transported, provided, obtained, or 

maintained by any means Jane Doe 1 and Jane Doe 2; 2) in or affecting state 

commerce; 3) that he did so knowing or in reckless disregard of the fact that 

Jane Doe 1 and 2 had not attained the age of 18 years or that he had a 

reasonable opportunity to observe them; and 4) that he did so knowing or in 

reckless disregard of the fact that they would be caused to engage in a 

commercial sex act. See 18 U.S.C. § 1591(a), (c). In isolating discrete elements 

of the crime of sex trafficking of a child, the questions conform to the 

formulation approved by the Advisory Committee Notes. See FED R. EVID. 704 

advisory committee’s note to 1972 proposed rules. The government did not ask 

Halbert or Campbell “do you believe that the defendant committed the offense 

of sex trafficking of a child?” Such a question is “phrased in terms of 

inadequately explored legal criteria.” FED R. EVID. 704 advisory committee’s 

note to 1972 proposed rules. Rather, the government asked Halbert and 

Campbell for their opinion regarding specific factual building blocks of the 

 Case: 17-10746 Document: 00514606524 Page: 16 Date Filed: 08/20/2018
No. 17-10746

17

ultimate crime. In that sense, the questions are eliciting “a mere explanation 

of the [witness’s] analysis of facts which would tend to support a jury finding 

on the ultimate issue.” Speer, 30 F.3d at 610.7

To the extent the district court erred in admitting the above testimony, 

such an error was not “so clear or obvious that the trial judge and prosecutor 

were derelict in countenancing it, even absent the defendant’s timely 

assistance in detecting it.” Trejo, 610 F.3d at 319 (internal quotations omitted). 

While it is well-settled law in this circuit that lay witness opinions amounting 

to legal conclusions are inadmissible, the line between an impermissible legal 

conclusion and “explanation of a [witness’s] analysis of facts” is somewhat 

blurry. The example provided by the Advisory Committee Notes to Rule 704 is 

helpful but not always conclusive. Moreover, the distinction is rarely dealt with 

in depth in the case law, as these types of challenges are often reviewed 

following a jury trial for plain error and can be disposed of on the third or fourth 

prong. See, e.g., McGee, 821 F.3d at 649; Izydore, 167 F.3d at 218. 

Furthermore, Keys has not shown a “reasonable probability that, but for 

[the error claimed], the result of the proceeding would have been different.” 

Holmes, 406 F.3d at 365 (alteration in original) (internal quotations omitted). 

The volume and quality of the evidence against Keys is staggering. See EspinoRangel, 500 F.3d at 400 (explaining that even if the admission of the testimony 

was plainly erroneous, the error is harmless if the remaining evidence at trial 

was sufficient to support the jury’s verdict). Both victims testified at length 

about their experiences at trial, and the record indicates that their live 

testimony was consistent with their previous accounts. Their accounts were 

 

7 The testimony was also “(a) rationally based on the witness’s perception; (b) helpful 

to clearly understanding the witness’s testimony or to determining a fact in issue; and (c) not 

based on scientific, technical, or other specialized knowledge within the scope of Rule 702.” 

FED R. EVID. 701. The defendant does not challenge the admissibility of the testimony under 

Rule 701.

 Case: 17-10746 Document: 00514606524 Page: 17 Date Filed: 08/20/2018
No. 17-10746

18

corroborated by hotel, phone, and internet records. Keys admitted to a 

substantial amount of the conduct in his police interview. Given the evidence 

presented at trial, it is difficult to imagine Keys would have obtained a more 

favorable outcome absent the challenged testimony.

The district court did not err in admitting Halbert and Campbell’s 

testimony. Even if the testimony was admitted in error, Keys has not met his 

burden to demonstrate that the error was obvious or that, absent the error, 

there is a reasonable probability the result of his trial would have been 

different.

2. Opinion testimony pertaining to Keys’s truthfulness

Halbert’s testimony regarding the veracity of Keys’s statement to police 

is not an impermissible legal conclusion—it is an opinion of fact. It therefore 

does not run afoul of Rule 704(a)’s proscription of opinion testimony on an 

ultimate legal issue.8 Accordingly, the source of the alleged problem with this 

subset of Halbert’s testimony must be Rule 701. See, e.g., United States v. 

Churchwell, 807 F.3d 107, 118–19 (5th Cir. 2015) (assessing non-expert

testimony regarding the defendant’s veracity under Rule 701). Keys incorrectly 

objects to the admission of Halbert’s testimony on the basis of Rule 704(b).

Accordingly, Keys has likely waived any Rule 701-specific challenges to the 

testimony for failure to adequately brief the issues. See Williams v. Parker, 843 

F.3d 617, 622 n.14 (5th Cir. 2016). Regardless, Halbert’s testimony meets the 

requirements of Rule 701, and it was therefore properly admitted. 

Keys objects to Halberts’ testimony that: 1) Keys minimized his role in 

facilitating the girls’ prostitution; 2) Keys was not completely honest during 

 

8 To the extent Keys objects on the basis that Halbert’s opining Keys lied during his 

interview is an indirect way of testifying to Keys’s guilt or innocence, he identifies no 

authority that indicates this type of “veracity” testimony is improper because of some 

hypothetical, twice-removed, downstream effect on that ultimate legal conclusion. 

 Case: 17-10746 Document: 00514606524 Page: 18 Date Filed: 08/20/2018
No. 17-10746

19

his interview; 3) he believed Keys was lying when he said that he got rid of the 

girls after learning that they were underage; and 4) he believed Keys was lying 

when he stated that he made contact with Jane Doe 1 after she left him to tell 

her to stop engaging in the lifestyle and to warn the apartment’s residents that 

she was underage. For these opinions to be admissible, they must be rationally 

related to Halbert’s perception, helpful to understanding his testimony or to 

determining a fact in issue, and not based on scientific, technical, or other 

specialized knowledge. See FED R. EVID. 701. Again, an opinion is not 

objectionable merely because it encompasses an ultimate issue of fact for the 

jury’s determination such as the veracity of a defendant’s prior statements. See 

FED R. EVID. 704(a); Churchwell, 807 F.3d at 118.9

It was not error to admit Halbert’s testimony. First, the testimony was 

certainly based on his personal perceptions. Halbert was one of the three 

agents present when law enforcement interviewed Keys. He participated 

actively in the questioning and he was able to observe, over some time, Keys’s 

demeanor and the inconsistencies in his story. Moreover, Halbert’s testimony 

was helpful. His opinion based on his observations gave context to Keys’s 

statements and assisted the jury in understanding Halbert’s interview 

tactics—which the defense sought to use against him on cross-examination. 

The defense also attempted to highlight the fact that Halbert had admitted 

Keys had told the truth about some things during his interview. To the extent 

that the defense wanted to capitalize on Halbert’s admissions that Keys had 

been partially honest, Halbert’s testimony that he did not think Keys was 

being truthful about a number of critical facts was undoubtedly beneficial to 

 

9 In the only case cited by Keys that speaks directly to testimony regarding the 

truthfulness of a defendant’s statements, the First Circuit held that the district court abused 

its discretion in admitting the testimony because, in that particular circumstance, it was not 

helpful—not simply because it touched on an ultimate issue in the case. See United States v. 

Sanabria, 645 F.3d 505, 516 (1st Cir. 2011).

 Case: 17-10746 Document: 00514606524 Page: 19 Date Filed: 08/20/2018
No. 17-10746

20

the jury. See Churchwell, 807 F.3d at 119 (stating that the challenged 

testimony was “appropriate, especially after the defense elicited testimony 

from [the witness] that [the defendant] was truthful at some point”). Lastly, it 

is clear that Halbert’s opinion was not based on scientific, technical, or other 

specialized knowledge. Accordingly, the district court did not err in admitting 

Halbert and Campbell’s testimony at trial. 10

V

For the foregoing reasons, we AFFIRM. 

 

10 Even if admitting the testimony was error, and even if that error was clear or 

obvious, Keys has failed to meet his burden to demonstrate that, absent the alleged error, 

the result of his trial would have been different for the same reasons as outlined in Section 

IV(1), supra. 

 Case: 17-10746 Document: 00514606524 Page: 20 Date Filed: 08/20/2018