REVISED APRIL 15, 2008

IN THE UNITED STATES COURT OF APPEALS

FOR THE FIFTH CIRCUIT

No. 07-40245

UNITED STATES OF AMERICA

Plaintiff - Appellee

v.

APOLINAR GRACIA, JR.

Defendant - Appellant

Appeal from the United States District Court 

for the Southern District of Texas

USDC No. 1:06-cr-00006-2

Before WIENER, BARKSDALE, and OWEN, Circuit Judges.

WIENER, Circuit Judge:

Defendant-Appellant Apolinar Gracia, Jr. traveled across the border

bridge between Matamoros and Brownsville as a passenger in a car driven by an

older female friend. The car contained approximately fifty kilograms of cocaine

hidden in a false floor. A jury convicted Gracia on four related drug counts.

Convinced that, during rebuttal closing argument, the government improperly

bolstered its key witnesses, the agents who heard Gracia’s unrecorded

confession, and that this bolstering constituted reversible plain error, which

seriously affected the fairness, integrity, and public reputation of those

proceedings, we reverse Gracia’s conviction and remand his case for a new trial.

United States Court of Appeals

Fifth Circuit

F I L E D

March 31, 2008

Charles R. Fulbruge III

Clerk
No. 07-40245

2

I. FACTS AND PROCEEDINGS

In December 2005, Gracia was a passenger in a gold Chevrolet Impala

when it was stopped at the Brownsville and Matamoros (“B&M”) International

Bridge while crossing into Texas from Mexico. Driving the car was Oralia

Valenzuela-Montoya, an older woman with whom it appears Gracia had a close,

platonic relationship. When the Treasury Enforcement Communication System

(“TECS”) generated a “hit” on the Impala’s license plate number, indicating that

the car might contain illegal narcotics, border patrol agents referred the car to

a secondary inspection area, where a detection dog alerted to the presence of

drugs. Further investigation revealed a sophisticated hidden compartment in

the floor of the vehicle which held forty-four packages containing a total of fifty

kilograms of cocaine with an estimated street value of at least $500,000. 

Gracia and Valenzuela-Montoya were escorted to separate interview rooms

in which they were detained by agents. Some time later, the pair was formally

placed under arrest after the discovery of the cocaine. Thereafter, at

approximately 3:30 a.m., Agent Richard Perez began questioning Gracia

following his waiver of his Miranda rights. At trial, Agent Perez testified that,

from the beginning, Gracia agreed to provide the agents with a statement.

Although Gracia had continued to deny that he knew the quantity or type of

drugs contained in the Impala, he acknowledged he had been stopped and

detained on this occasion because of a problem with either cocaine or marijuana

in the Impala, and that he was to have received $1,000 for accompanying

Valenzuela-Montoya in the Impala when it crossed the B&M Bridge. 

Despite these disclosures by Gracia, Agent Perez believed that Gracia was

“not being entirely truthful,” so he had Valenzuela-Montoya brought into

Gracia’s interview room. According to Agent Perez, Valenzuela-Montoya urged

Gracia “to tell the whole truth, so the agents could help them.” Gracia contends

that Valenzuela-Montoya also communicated a message to him through head
No. 07-40245

3

nods and eye signals, although the agents who were present dispute this

account. Valenzuela-Montoya was then removed from Gracia’s interview room.

According to the agents, Gracia was noticeably moved by ValenzuelaMontoya’s visit, and volunteered that a man named Gerardo or Geraldo had

made an arrangement with Gracia to transport the cocaine-laden Impala to

Houston once it had cleared the border. Gracia provided details to Agent Perez

about the history and method of the smuggling operation in which he had

participated. The agents neither obtained a written statement from Gracia nor

recorded his utterances. They did seize $1,000, but from Valenzuela-Montoya,

not Gracia.

Early in 2006, Gracia was indicted in the Southern District of Texas on

four counts: (1) conspiracy to possess with intent to distribute more than five

kilograms of cocaine in violation of 21 U.S.C. §§ 846, 841(a)(1), and 841(b)(1)(A);

(2) possession with intent to distribute more than five kilograms of cocaine in

violation of 21 U.S.C. §§ 841(a)(1) and 841(b)(1); (3) conspiracy to import more

than five kilograms of cocaine in violation of 21 U.S.C. §§ 963, 952(a), and

960(b)(1); and (4) importation of more than five kilograms of cocaine in violation

of 21 U.S.C. §§ 952(a) and 960(b)(1). In March 2006, Gracia proceeded to jury

trial, at the conclusion of which the jury returned a verdict of guilty on all four

counts. A year later, the district court sentenced Gracia to concurrent terms of

imprisonment of 168 months on each ofthe four counts, and concurrentfive-year

terms of supervised release on each. Gracia timely filed a notice of appeal.

II. ANALYSIS

Gracia contends that three instances of prosecutorial misconduct at trial

constitute grounds for reversal: The prosecutor’s (1) references to ValenzuelaMontoya’s guilt; (2) comments on Gracia’s silence in custody and decision not to

testify; and (3) bolstering of the agents’ testimony during rebuttal closing

argument. For the reasons set forth below, we agree that the prosecutor’s
No. 07-40245

1 United States v. Mares, 402 F.3d 511, 515 (5th Cir. 2005). Gracia speciously asserts

on appeal that he did, in fact, object to three of the government’s four allegedly improper

statements. After the prosecutor voiced two of his allegedly improper statements and before

voicing allegedly improper statements three and four, Gracia did raise an objection. Gracia

did not object, however, on the basis of improper witness bolstering, but because the facts

introduced were not in evidence. Gracia’s sole objection was thus completely non-topical, viz.,

unrelated to improper witness bolstering, and non-contemporaneous with all but one of the

government’s allegedly improper statements. For purposes of our determination of the

applicable standard of review, Gracia did not make a valid contemporaneous objection to the

government’s allegedly improper statements. See United States v. Gallardo-Trapero, 185 F.3d

307, 322 n.7 (5th Cir. 1999) (holding that plain error review applied because defendant’s

attorney’s objection, although raised, was based on topic unrelated to matter on appeal).

2 We apply plain error review to allegedly improper comments for which there was no

objection, as in the instant case. United States v. Fields, 483 F.3d 313, 360 (5th Cir. 2007)

(citing Gallardo-Trapero, 185 F.3d at 321). In contrast, the trial court’s admission of objectedto comments are reviewed for abuse of discretion, which involves two steps: (1) we must first

decide whether the prosecutor made an improper remark and (2) if an improper remark was

made, we must determine whether the remark affectedthe substantial rights ofthe defendant.

Id. at 358 (citing United States v. Insaulgarat, 378 F.3d 456, 461 (5th Cir. 2004), cert. denied,

No. 07-6395, 2008 WL 114089 (U.S. Jan. 14. 2008)).

3 United States v. Jones, 484 F.3d 783, 792 (5th Cir. 2007) (citing Mares, 402 F.3d at

520).

4 Mares, 402 F.3d at 520 (citing United States v. Cotton, 535 U.S. 625, 631 (2002)).

4

bolstering of the agents’ testimony constituted reversible plain error. As we

reverse and remand on this basis, we do not address whether the prosecutor’s

references to Valenzuela-Montoya’s guilt and comments on Gracia’s silence also

constitute independent or cumulative grounds for reversal. 

A. Standard of Review

Gracia’s trial counsel did not contemporaneously objectto the prosecutor’s

comments regarding the agents’testimony,1so we apply the plain error standard

of review.2 To demonstrate reversible plain error, Gracia had to show that (1)

there is error; (2) it is plain; and (3) it affected his substantial rights.3 Even if

he could meet that burden, we still would have discretion to decide whether to

reverse, which we generally will not do unless the plain error seriously affected

the fairness, integrity, or public reputation of the judicial proceeding.4
No. 07-40245

5 Gallardo-Trapero, 185 F.3d at 322. 

5

B. Merits

Gracia points to four remarks by the prosecutor that bolstered the

credibility of the agents who interviewed him. First, the prosecutor expressed

his opinion to the jury that the agents were “very, very credible” witnesses

(“Statement One”). Second, the prosecutor asked the jurors rhetorically whether

they thought that an agent “who has worked as a law enforcement agent for

many years, that is his career, that is his chosen life, a man from this area, a

man with a family, do you think that he would throw all that away by taking

this stand and taking an oath and lying to you to get Mr. Gracia”; and whether

the agents “would put their careers and criminal prosecution on the line for

committing the offense of aggravated perjury” (“Statement Two”). Third, the

prosecutor told the jury: “I’m going to ask you to respect their efforts as law

enforcement officials and to believe the testimony thatthey offered”(“Statement

Three”). Fourth, the prosecutor admonished the jurors that, to acquit Gracia,

they would have to believe that the agents “got out of bed” on the day they

arrested Gracia and decided that this was “the day that [they] were going to

start [a] conspiracy to wrongfully convict Mr. Gracia” (“Statement Four”).

Gracia insists that these remarks constituted reversible plain error. The

government concedes that Statements One and Three may have been improper,

but nevertheless contends that all four statements were harmless error. 

1. All four of the prosecutor’s statements were errors.

We first turn to the question whether the statements at issue constituted

error, defined as “deviation from a legal rule.”5 When we do, we conclude that

each remark highlighted by Gracia indisputably was an improper, or erroneous,

deviation from a legal rule. The Supreme Court’s decision in Berger v. United

States makes clear that a personal assertion by a prosecutor of a government
No. 07-40245

6 295 U.S. 78, 88 (1935) (“It is fair to say that the average jury . . . has confidence that

these obligations, which so plainly rest upon the prosecuting attorney, will be faithfully

observed. Consequently, improper suggestions, insinuations, and, especially, assertions of

personal knowledge are apt to carry much weight against the accused when they should

properly carry none.”); see also United States v. Young, 470 U.S. 1, 18-19 (1985) (“The

prosecutor’s vouching for the credibility of witnesses and expressing his personal opinion

concerning the guilt of the accused pose two dangers: such comments can convey the

impression that evidence not presented to the jury, but known to the prosecutor, supports the

charges against the defendant and can thus jeopardize the defendant’s right to be tried solely

on the basis of the evidence presented to the jury; and the prosecutor’s opinion carries with it

the imprimatur of the Government and may induce the jury to trust the Government’s

judgment rather than its own view of the evidence.”). 

7 ABA Criminal Justice Section Standards, Argument to the Jury, Standard 3-5.8.

8 Gallardo-Trapero, 185 F.3d at 320.

9

Id.

10 Berger, 295 U.S. at 88; see also Hodge v. Hurley, 426 F.3d 368, 378-80 (6th Cir. 2005)

(holding that two statements by prosecutor commenting on veracity of two key witnesses,

including remark that one of witnesses and her family were “absolutely believable” were

improper and constituted plain error). 

11 United States v. Brown, 451 F.2d 1231, 1236 (5th. Cir. 1971) (court reversed

conviction because prosecutor improperly remarked in closing argument that he thought

agent/witness did “a real good job” and “was doing his duty to his country”). 

6

witness’s credibility is impermissible.6 The American Bar Association’s

standards for prosecutors echo this sentiment: “The prosecutor should not

express his or her personal belief or opinion as to the truth or falsity of any

testimony or evidence or the guilt of the defendant.”7 The government may not

cloak a witness in its “protective mantle.”8 A prosecutor may argue fair

inferences from the evidence that a witness has no motive to lie, but cannot

express a personal opinion on the credibility of witnesses.9

As the government concedes, it is impermissible per se for a prosecutor to

offer personal assurances to the jury that government witnesses are telling the

truth, as in Statement One,10 or to tell the jury that law enforcement witnesses

should be believed simply because they were doing their job, as in Statement

Three.11
No. 07-40245

12 Gallardo-Trapero, 185 F.3d at 319-21 (court found improper closing argument in

which prosecutor asked “do you think that agents for the federal government and a prosecutor

for the federal government, for the United States of America, are going to risk their career and

get on the stand . . . and commit perjury and risk their career. It’s not going to happen, ladies

and gentlemen.”); see also United States v. Goff, 847 F.2d 149, 165 (5th Cir. 1988) (prosecutor’s

statements invoking “the dignity of his oaths and office as well as the sanctity of state and

federal governmental agencies in order to persuade the jury that they should find appellants

guilty . . . were impermissible”). Cf. United States v. Martinez-Larraga, 517 F.3d 258, 265, 271

(5th Cir. 2008) (holding that it was not improper for prosecutor to ask jury why government

agents “would . . . get up here and try to make up lies or make up suggestions,” and remind

jurors that agents “were there,” and were “telling you what they saw.” The court stated that,

“[u]nlike the remarks atissue in Gallardo-Trapero,the prosecutor’s remarks didnotimply that

because they are government agents, the witnesses would not lie. They also do not imply that

as a general rule, federal law enforcement agents tell the truth in court . . . . The prosecutor

simply suggested that the jury should infer from the facts that the agents did not have a

reason to lie.”) (internal citation omitted). We note that Statement Two is more similar to the

statements at issue in Gallardo-Trapero than those in Martinez-Larraga, as it implied that,

because “they are government agents, the witnesses would not lie.” Id.

13 Goff, 847 F.2d at 164 (“The prosecutor further suggested that in order to find

appellants not guilty, the jury would have to believe that several governmental agencies and

even perhaps federal judges had engaged in a malevolent and illegal conspiracy to convict

them. This also was improper argument . . . . Confronted with such argument, jurors could be

expected to feel that in order to find appellants innocent they would have to abandon

confidence in the integrity of government.”) (citing United States v. Dorr, 636 F.2d 117, 119-21

(5th Cir. 1981); United States v. Herrera, 531 F.2d 788, 790 (5th Cir. 1976)).

7

Although the government does not concede that Statements Two and Four

were errors, we cannot meaningfully distinguish the prosecutor’s admittedly

improper remarks and those that the government does not concede were errors.

All four statements urge conviction based not on the objective evidence before

the jury or its independent judgment of the witnesses’ credibility, but on

something uniquely within the prosecutor’s knowledge. We have held it

improper for a prosecutor to ask a jury the rhetorical question whether federal

agents would risk their careers to commit perjury, as in Statement Two.12 We

have deemed improper an unequivocal statement by a prosecutor that, for the

jurors to believe the defense’s account, they would have to believe in a

government conspiracy, as in Statement Four.13 The subject remarks of Gracia’s

prosecutor share the same basic flaw: A prosecutor’s impermissible assertion of
No. 07-40245

14 185 F.3d at 319-20.

15 United States v. Garza, 608 F.2d 659, 663 (5th Cir. 1979) (quoting Hall v. United

States, 419 F.2d 582, 583-84 (5th Cir. 1969)).

16 United States v. De Jesus-Ojeda, 515 F.3d 434, 445 (5th Cir. 2008) (citing United

States v. Calverley, 37 F.3d 160, 162-64 (5th Cir. 1994)). 

17 In reference to one of the agents, counsel for Gracia noted in his closing argument

that “even when we[] . . . have no incentive to lie, it’s human nature . . . . You’re a witness for

the government. You tend sometimes to recall things a little differently” (Record at 487). Soon

after, Gracia’s attorney re-emphasized this the-agents-are-lying theme: “And sometimes even

after they [the agents] take an oath in court to swear to tell the truth, they still say something

that was not true. And they’ll swear by it, but it wasn’t true” (Id. at 488). Later in his closing

argument, Gracia hammered home his assertion that the agents were not telling the truth:

“I’m just telling you that people who testify sometimes testify to what they think they

remember, but it’s not what they remember” (Id. at 490).

8

his own credibility, or that of the government, to bolster the credibility of a

witness. As we held in United States v. Gallardo-Trapero, “it is particularly

improper, indeed, pernicious, for a prosecutor to seek to invoke his personal

status as the government’s attorney or the sanction of the government itself as

a basis for convicting a criminal defendant.”14 As the “power and force of the

government tend to impart an implicit stamp of believability to what the

prosecutor says,”15 — here, that the agents were credible witnesses — all four of

the prosecutor’s statements constituted error. 

2. The prosecutor’s errors were plain.

We next turn to the question whether the prosecutor’s errors were plain,

which we define as “clear and obvious.”16 The government urges us to put the

prosecutor’s remarks in the context of counsel for Gracia’s earlier innuendo that

the agents were less than forthcoming. We agree that the magnitude of the

prejudicial effect ofthe prosecutor’s remarks should not be weighed in a vacuum,

and we recognize that the trial record contains statements by counsel for Gracia

indirectly implying thatthe agents might not be altogether truthful.17 Thus, the

prosecutor’s attempts to vouch for the agents’ credibility should be seen as a
No. 07-40245

18 United States v. Fields, 483 F.3d 313, 358 (5th Cir. 2007) (citing United States v.

Wicker, 933 F.2d 284, 292 (5th Cir. 1991); United States v. Iredia, 866 F.2d 114, 118 (5th Cir.

1989)) (emphasis added). 

9

response to Gracia’s effort to discredit the agents. We weigh the magnitude of

the prejudice resulting from the prosecutor’s obviously improper statements in

this context. 

Nevertheless, the context in which each of the prosecutor’s improper

remarks must be tested is also shaped by his other three improper remarks.

Just as we must evaluate the prosecutor’s statements in the context of Gracia’s

earlier attempts to suggest that the agents could be prevaricating, we cannot

separately consider each of the prosecutor’s erroneous remarks in a framework

that excludes his other near-simultaneous, similar attempts to bolster the

credibility of the agents. Although we recognize that, “in assessing prejudice,

occurrences of prosecutorial misconduct ordinarily must be viewed

individually,”18 the four remarks about which Gracia cries foul occurred within

minutes of each other during the prosecutor’s rebuttal closing argument. In this

instance, the cumulative effect of these proximate comments was greater than

the sum of its parts. The prejudicial effect of the prosecutor’s statements thus

must be weighed in pari materiae. Our analysis would be deficient if we were

simply to assess the isolated prejudice resulting from each error standing alone,

without temporally and substantively connecting each remark to the prosecutor’s

witness-bolstering efforts in his rebuttal closing argument. 

When we review the prosecutor’s remarks within this context, we conclude

that his errors were clear and obvious. The four at-issue statements were

neither isolated nor limited, but were cumulative components of a single

diatribe, indisputably geared toward bolstering the agents’ testimony, and thus

constituting plain error.

3. The prosecutor’s statements affected Gracia’s substantial rights.
No. 07-40245

19 Id.

20 United States v. Holmes, 406. F.3d 337, 356 (5th Cir. 2005) (internal quotation marks

and citations omitted).

21 See FED. R. CRIM. P. 52(a) (“Any error, defect, irregularity, or variance that does not

affect substantial rights must be disregarded”); see also United States v. Jones, 839 F.2d 1041,

1050 (5th Cir. 1988) (“Proper supervision requires us atleastto balance the need to protect the

integrity of federaltrials against the practical interest in giving finality to an accurate and fair

verdict; we cannot by our supervisory power reverse a conviction for trial error that was

harmless.”). 

10

This case ultimately turns on the third step in our analysis — whether the

prosecutor’s improper statements affected Gracia’s substantial rights. This step

“sets a high bar.”19 “The determinative question is whether the prosecutor’s

remarks cast serious doubt on the correctness of the jury’s verdict.”20

Gracia contends that the prosecutor’s remarks did so by placing the

government’s weighty imprimatur on the only evidence linking him to a crime,

i.e., the agents’ testimony. The government counters that even if the

prosecutor’s statements were legally improper and thus erroneous, they were

harmless, i.e., Gracia’s substantial rights were not affected, thereby preventing

the statements from rising to the level of reversible plain error.21

To determine whether the prosecutor’s errors affected Gracia’s substantial

rights, we first examine the effect of the court’s cautionary instructions. The

district court did help to mitigate the prejudicial effect of the prosecutor’s

violations somewhat by generically instructing the jury that it was their “duty

to base [their] verdict solely upon the evidence without sympathy or prejudice,”

that they “must consider only the evidence presented during the trial,” to

“[r]emember that any statements, objections or arguments made by the lawyers

are not evidence . . . ,” and to remember that “[w]hat the lawyers say is not

binding . . . .” “We presume that such instructions are followed unless there is

an overwhelming probability that the jury will be unable to follow the

instruction and there is a strong probability that the effect of the improper
No. 07-40245

22 United States v. Gallardo-Trapero, 185 F.3d 307,321 (5th Cir. 1999) (internal

quotation marks and citations omitted).

11

statement is devastating.”22 Gracia is correct, of course, that the court could

have crafted more subjectively detailed instructions geared toward mitigating

the prejudicial effect of these particular erroneous remarks, but we do not agree

that it is invariably impossible to purge the taint of a prosecutor’s prejudicial

comments with merely generic cautionary instructions. The generalized

instructions the court gave to the jury did serve, if only moderately,to reduce the

degree of prejudice of the tainted remarks.

This brings us to the next element of our consideration, i.e., the strength

or weakness of the government’s case againstthe defendant. Even crediting the

district court’s cautionary instructions, we are convinced that the prosecutor’s

statements, considered as a whole, prejudicially affected Gracia’s substantial

rights when viewed in comparison to the dearth of other evidence of Gracia’s

guilt. Simply put, other than the agents’ testimony, there is none. Gracia’s

alleged confession was neither recorded nor transcribed. The sophisticated

hidden compartment containing the drugs beneath the floor of the car would not

have been apparent to an unknowing passenger. The $1,000 seized by the

agents was taken from Valenzuela-Montoya, not from Gracia. Gracia’s

purported contactin Houston (Gerardo or Geraldo) was never located. Although

Gracia did try to make himself gag by putting his fingers down his throat during

the early stages of his detention at the B&M Bridge, guilty knowledge cannot be

presumed, as the government urges, from such a tertiary circumstantial fact,

especially given the fact of Gracia’s serious health problems which require

frequent dialysis treatments. Neither can guilty knowledge be inferred from the

factthat Gracia did not appear surprised or upset when the agents told him that

they had discovered drugs in the Impala. Indeed, if Gracia had appeared upset

or surprised, the government would likely have urged us to infer guilty
No. 07-40245

23 United States v. Zapata-Ibarra, 223 F.3d 281 (5th Cir. 2000) (Wiener, J., dissenting)

(criticizing the attribution of guilt from any number of opposite factors). 

24 608 F.2d 659, 665 (5th Cir. 1979) (court reversed conviction on plain-error review,

holding that “we think it beyond question that the prosecutor’s improper comments, taken as

a whole, affected substantial rights of the defendant”).

25 551 F.2d 1386, 1389 (5th Cir. 1977) (“As we have stated above the government

concedes that it was error for counsel to vouch for this government witness. However, it is

12

knowledge from that, too.23 The simple reality of this case is that Gracia’s

conviction turned entirely on the jury’s evaluation ofthe credibility ofthe agents

who interviewed him atthe B&M Bridge. Plainly put, absent the jury’s crediting

of the agents’ testimony, Gracia could not have been found guilty beyond a

reasonable doubt on the paucity of other evidence. 

The prosecutor’s imprudent statements unacceptably placed the

government’s weighty stamp of approval on the only evidence indicating Gracia

knew of the cocaine in the Impala’s floor, viz., the agents’ testimony. The

cumulative prejudice resulting from the prosecutor’s four erroneous statements

in quick succession clears the high bar necessary to affect Gracia’s substantial

rights and thus to constitute reversible plain error when viewed in the context

of the minor mitigating effect of the generic cautionary instructions and the

dearth of evidence of guilt other than the bolstered testimony of the agents. 

The prejudice resulting from the prosecutor’s comments seriously affected the

fairness, integrity, and public reputation of Gracia’s judicial proceeding. 

The case law is replete with examples of improper witness bolstering by

prosecutors found to be reversible plain error. In United States v. Garza, for

example, we held that a prosecutor’s repeated vouching for the credibility of

witnesses constituted reversible plain error.24In United States v. Corona, we

held that a prosecutor’s statement that he was “proud of” one of the

government’s witnesses affected the defendant’s substantial rights and

constituted reversible plain error.25 In addition to this court, other circuit courts
No. 07-40245

contended by the United States that this was harmless error and it should be overlooked. This

court has passed too many times on this kind of comment by prosecutors to permit it to

continue by allowing it to be brushed under the rug under the harmless error doctrine.”)

(internal citations omitted). 

26 See, e.g., Hodge v. Hurley, 426 F.3d 368, 378-79 (6th Cir. 2005) (“The prosecutor’s

numerous statements on witness credibility — often unsupported by any rational justification

other than an assumption that [defendant] was guilty — cannot avoid suggesting to the jury

that the prosecutor knows something they do not. Moreover, because these statements by the

prosecutor were not coupled with a more detailed analysis of the evidence actually adduced at

trial, they convey an impression to the jury that they should simply trust the State’s judgment

that [the government’s witness] was a credible witness and that the defendant’s witnesses

were non-credible, if not perjurious. This misconduct is especially prejudicial in this case given

the extent to which the jury’s determination as to [the defendant’s] guilt or innocence hinged

almost entirely on the credibility of [the defendant] and [the government’s witness.”); United

States v. Francis, 170 F.3d 546, 549 (6th Cir. 1999) (prosecutor’s statements that government

witnesses were credible because they would not jeopardize plea agreements were reversible

error because no adequate curative instructions were given and evidence of defendants’ guilt

was not overwhelming); United States v. Manning, 23 F.3d 570, 572-75 (1st Cir. 1994)

(prosecutor’s statement that government witnesses could not lie on stand was reversible error

because case turned on whether government witnesses or defendant testified truthfully, no

curative instructions were given, and other misconduct occurred); United States v.

Dispoz-O-Plastics, Inc., 172 F.3d 275, 287 (3d Cir. 1999) (prosecutor’s appealto jurors’ common

sense in vouching for credibility of government witnesses was reversible error because it likely

had substantial effect on trial outcome); United States v. Cotnam, 88 F.3d 487, 500 (7th Cir.

1996) (prosecutor’s repeated vouching for credibility of key witness was reversible error

because vouching was prejudicial to defendant and evidence of defendant’s guilt was not

overwhelming); United States v. Kerr, 981 F.2d 1050, 1052-54 (9th Cir. 1992) (prosecutor’s

vouching for credibility of four government witnesses was reversible error because witnesses’

testimony was crucialto prosecutor’s argument, curative instructions did not neutralize harm

of statements, and evidence connecting defendant to conspiracy was only indirect); United

States v. Eyster, 948 F.2d 1196, 1207 (11th Cir. 1991) (prosecutor’s vouching for credibility of

key witness was reversible error because undermining credibility of witness was essential to

defense and reasonable probability existed that but for prosecutor’s improper comments

outcome of proceeding would have been different).

27 See, e.g., United States v. Fields, 483 F.3d 313, 360 (5th Cir. 2007) (“Neither

statementis so grave, however,thatit risked prejudicing substantially the jury’s deliberations.

In light of the court's instructions and the strength of the evidence against Fields, Fields has

not shown that either remark casts doubt on the correctness of the jury’s verdict.”) ; GallardoTrapero, 185 F.3d at 320-21 (5th. Cir. 1999) (“We conclude that the prosecutor’s remarks

13

have held similar instances of witness bolstering to be reversible plain error.26

We acknowledge that, more often than not, we have held instances of

witness bolstering by prosecutors to be error but have gone on to find such error

harmless rather than reversing the jury conviction of a defendant.27 The instant
No. 07-40245

during closing argument did not prejudicially affect the substantive rights of the defendants

. . . . Given the strident advocacy on both sides of this case and the numerous witnesses, pieces

of evidence, and issues placed before the jury, we cannot say that the prosecutor’s statements

overshadowed what had come before and unduly prejudiced the Appellants’ case. In addition,

the district court helped to mitigate any prejudicial effect by instructing the jury to base their

decision solely upon the testimony and evidence presented . . . .”).

14

matter is distinguishable from the cases in which we have refused to reverse

convictions, however, because of the degree of the prosecutor’s violations in

comparison to the dearth of evidence of Gracia’s guilty knowledge. As Gracia

could not have been convicted withoutthe agents’testimony, we cannot conclude

that the prosecutor’s bolstering constituted an unprofessional but harmless

attempt to right the scale and rebut defense counsel’s earlier veiled innuendo

that the agents might be less than fully truthful. In this case, the jury’s

determination of guilt or innocence hinged entirely on whether Gracia had

knowledge of the hidden drugs and that, in turn, hinged entirely on the

credibility of the agents. The relative strength of the government’s case is

telling. The prosecutor’s plainly erroneous statements led the jury to substitute

the government’s credibility assessment of its own agents for the jurors’

independent credibility call, thereby casting serious doubt on Gracia’s guilty

verdict. We are convinced that, under the discrete facts of this case, the

prosecutor’s remarks affected Gracia’s substantial rights and seriously affected

the fairness, integrity, and public reputation of his trial. 

III. CONCLUSION

Witness bolstering is particularly injurious when, as here, it involves the

testimony of the only witnesses (and virtually the only inculpatory evidence)

against a defendant. The testimony of the agents was the only evidence tending

to prove Gracia’s knowledge of the presence of drugs in the car’s secret

compartment. We cannot permit the prosecutor’s remarks to be swept under the

rug by the broom ofthe harmless error doctrine. In this case, a slap-on-the-wrist

in obiter dicta will not suffice. The unmistakable misconduct in the bolstering
No. 07-40245

28 Berger v. United States, 295 U.S. 78, 88 (1935). 

15

of the government’s witnesses at Gracia’s trial is precisely the type of conduct

that cannot be condoned. It re-affirms the ageless wisdom of Berger: 

The United States Attorney is the representative not of an ordinary

party to a controversy, but of a sovereignty whose obligation to

govern impartially is as compelling as its obligation to govern at all;

and whose interest, therefore, in a criminal prosecution is not that

it shall win a case, but that justice shall be done.28

As Gracia’s prosecutor did not heed Berger’s admonition, he must be held

accountable for wrapping his witnesses in the government’s cloak of veracity and

invoking his personal status as the government’s attorney to assure the jury of

the credibility of those agents.

We hold that the prosecutor’s statements constituted reversible plain

error, which seriously affected the fairness, integrity, and public reputation of

Gracia’s judicial proceeding. Gracia’s conviction is therefore REVERSED and

his case is REMANDED to the district court for a new trial.