In the

United States Court of Appeals

For the Seventh Circuit

Nos. 99-2382, 99-2424 & 99-2425

United States of America,

Plaintiff-Appellee,

v.

Raul Cruz-Velasco, Ramiro S. Trevino,

and Joseph L. Cuevas, 

Defendants-Appellants.

Appeals from the United States District Court

for the Central District of Illinois, Urbana Division.

No. 97-CR-20037--Michael P. McCuskey, Judge.

Argued March 27, 2000--Decided August 17, 2000

 Before Flaum, Chief Judge, and Posner and Williams,

Circuit Judges.

 Flaum, Chief Judge. The defendants, Raul CruzVelasco, Ramiro S. Trevino, and Joseph L. Cuevas,

were each convicted of one count of conspiracy to

distribute more than one kilogram of heroin in

violation of 21 U.S.C. sec. 846 and sec.

841(b)(1)(A)(i) and one count of possession of

more than one kilogram of heroin with intent to

distribute in violation of 21 U.S.C. sec.

841(a)(1) and sec. 841(b)(1)(A)(i). The

defendants now appeal, alleging various errors on

the part of the district court. For the reasons

stated herein, we affirm the defendants’

convictions and sentences.

I. Background

 The conduct for which the defendants were

convicted and sentenced stems from two separate

drug transactions. Those transactions occurred

during the months of May and July of 1997.

1. The May Transaction

 During May 1997, defendant Cruz-Velasco stored

approximately five kilograms of heroin behind a

bar owned by Daniel Chavez in Edinburg, Texas. At

a meeting between Chavez, defendant Cruz-Velasco,

defendant Trevino, and Polo Garza, a bartender

who worked for Chavez, defendant Trevino told
Chavez that he wanted the heroin moved to Dallas,

Texas. Garza initially agreed to transport the

drugs to Dallas, and defendant Cruz-Velasco

stated that he would assist Garza by following

him during the trip. Although defendant Trevino

then proceeded to Dallas to await Garza’s

delivery, Garza never made the trip because he

could not obtain access to a vehicle.

 On May 16, 1997, defendant Trevino called

Chavez from Dallas and inquired as to why Garza

had not yet made the agreed-upon heroin delivery.

Chavez stated that he did not know Garza’s

whereabouts and explained that it was his

understanding that Garza was in Dallas.

Subsequent to this telephone conversation,

defendant Trevino visited Chavez at his bar and

informed him that defendant Cruz-Velasco would

pick up the heroin.

 Shortly after defendant Cruz-Velasco picked up

the heroin from Chavez, defendant Trevino again

met with Chavez and told him that Jose Villanueva

was willing to transport the heroin to Dallas. On

May 19, 1997, defendant Trevino, defendant CruzVelasco, Chavez, and Villanueva met behind

Chavez’s bar. Defendant Cruz-Velasco brought the

heroin with him to this meeting, and it was given

to Villanueva in ten small packages. Villanueva

then delivered the drugs to Dallas, arriving that

same day.

 When Villanueva arrived in Dallas, he met

defendant Cruz-Velasco and defendant Trevino and

the three men proceeded to a Dallas hotel. The

next morning Villanueva gave the heroin to

defendant Cruz-Velasco, who put the drugs in a

white pickup truck and left. Villanueva was paid

approximately $2,000 for this delivery.

 On May 20, 1997, defendant Cuevas, Guizar, and

Pablo Villamil flew from Chicago, Illinois to

Dallas where they met defendant Cruz-Velasco.

During this meeting, defendant Cruz-Velasco

delivered the heroin in his possession to

Villamil. Villamil then transported the heroin to

Chicago on a Greyhound bus and, upon his arrival

in Chicago, gave the heroin to an individual

named Hector Castenada. Villamil received $8,500

for his services.

2. The July Transaction

 In late June or early July 1997, defendant

Trevino hired Villanueva to transport five

kilograms of heroin from McAllen, Texas to

Chicago. Villanueva received ten packages of

heroin from defendant Cruz-Velasco and was

instructed by defendant Trevino to travel to an

area approximately eighty miles outside of
Chicago. Villanueva left Texas on July 3, 1997

with the heroin hidden in his car.

 When Villanueva arrived in Kankakee, Illinois on

July 4, 1997, he was instructed to go to Room 310

at the Days Inn in Kankakee. While Villanueva was

on his way to the Days Inn, he was stopped by a

Kankakee County Sheriff’s Department deputy. The

deputy searched Villanueva’s car and discovered

one kilogram of heroin in a black duffel bag.

Villanueva was arrested and taken to the Kankakee

detention center.

 Because of the quantity of drugs seized from

Villanueva, the Kankakee County Sheriff’s

Department contacted the Kankakee Area

Metropolitan Enforcement Group ("KAMEG"), a task

force organized to investigate mid-to-upper level

drug dealers. Members of KAMEG interviewed

Villanueva, who informed them that there was an

additional four kilograms of heroin hidden in his

car. Villanueva also agreed to participate in a

controlled sale.

 After receiving instructions on the controlled

sale, Villanueva went to Room 310 at the Days Inn

where he met defendant Trevino and defendant

Cruz-Velasco. After a brief conversation about

the drug transaction that was to take place,

Villanueva was instructed to drive to a Knights

Inn in Kankakee and wait. Members of KAMEG

followed Villanueva to the Knights Inn and gave

him further instructions on the controlled sale.

 Approximately five minutes after Villanueva left

the Days Inn, members of KAMEG observed defendant

Cuevas and Hector Castenada approach Room 310.

Defendant Cuevas carried a medium-sized gym bag

in his hand. When defendant Trevino answered the

door of Room 310, defendant Cuevas and Castenada

went inside. At approximately 2:17 p.m., law

enforcement officials observed defendant CruzVelasco and Castenada leave Room 310. Neither man

was carrying anything. 

 Defendant Cruz-Velasco and Castenada then

proceeded to the Knights Inn, where they received

a bag containing heroin from Villanueva.

Following this exchange, defendant Cruz-Velasco

got in Villanueva’s car. Castenada drove away

unaccompanied. Villanueva and defendant CruzVelasco then returned to the Days Inn, and

defendant Cruz-Velasco commented that the

delivery had been easy. 

 After exiting Villanueva’s car, defendant CruzVelasco returned to Room 310 at the Days Inn. A

few minutes later, defendant Cuevas left the Days

Inn in a black Mercedes-Benz. He was followed by

an unmarked police car. After several minutes in
which defendant Cuevas exited the highway

multiple times and appeared to be attempting to

evade the undercover police officer who was

following his car, a traffic stop was initiated

by a uniformed officer and defendant Cuevas was

arrested.

 At the same time that defendant Cuevas was

being followed, a sheriff’s deputy stopped

Castenada’s vehicle and arrested him. Upon a

search of Castenada’s vehicle, five kilograms of

heroin were discovered. Defendant Trevino and

defendant Cruz-Velasco were then arrested at the

Days Inn, and a search of the room revealed

$22,510 in cash, as well as notes, articles of

clothing, and a number of pagers. Defendant CruzVelasco, defendant Cuevas, defendant Trevino, and

Castenada were all interviewed by KAMEG, but none

of them admitted involvement in the drug

trafficking of which they were suspected.

3. The Trial

 The defendants were charged in a two-count

superseding indictment with one count of

conspiracy to possess with intent to distribute

more than one kilogram of heroin and one count of

possession of more than one kilogram of heroin

with intent to distribute. After a jury trial,

all three defendants were convicted on both

counts. On May 21, 1999, the defendants were

sentenced to 151 months imprisonment, a five-year

period of supervised release, and a mandatory

special assessment of $200. In addition,

defendant Cuevas was fined $300,000. The

defendants now appeal, arguing that the district

court made various errors during both the guilt

and sentencing phases of trial.

II. Analysis

 The defendants’ cases were consolidated both for

purposes of trial and appeal. Although the

various issues raised by each defendant overlap,

they are not identical. We therefore consider

each defendant’s contentions separately. However,

to the extent the defendants adopt the arguments

made by their co-appellants, the analysis of the

individual claims applies to all the appellants

to whom those issues are applicable.

A. Defendant Ramiro S. Trevino

1. The Expert Testimony of DEA Agent Joseph

Reagan

 During the defendants’ trial, the government

called DEA Agent Joseph Reagan to the stand to

testify as an expert witness about the nature,

structure, and characteristics of drug

trafficking operations. Defendant Trevino now
argues that in admitting this testimony, the

district court failed to apply the proper

standard for the admission of expert testimony as

enunciated by the Supreme Court in Daubert v.

Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579

(1993). We review whether the district court

properly followed the Daubert framework in

considering the admissibility of expert testimony

de novo, see United States v. Hall, 165 F.3d

1095, 1101 (7th Cir. 1999), but we review the

district court’s decision to admit Agent Reagan’s

testimony for an abuse of discretion, see Kumho

Tire Co. v. Carmichael, 526 U.S. 137, 152 (1999);

United States v. Clark, 192 F.3d 750, 756 (7th

Cir. 1999).

 Rule 702 of the Federal Rules of Evidence

provides that "[i]f scientific, technical, or

other specialized knowledge will assist the trier

of fact to determine a fact in issue" an expert

"may testify thereto." Fed.R.Evid. 702. The

Supreme Court has made clear that in applying

Rule 702, district courts serve a gatekeeping

function and must ensure that the expert

testimony at issue "both rests on a reliable

foundation and is relevant to the task at hand."

Daubert, 509 U.S. at 597; see Kumho, 526 U.S. at

147. Although the Daubert Court identified a

number of factors to be considered when

evaluating the admissibility of expert testimony-

-including testing, peer review, error rates, and

acceptability within the relevant professional

community--these factors do not establish a

definitive checklist. See Kumho, 526 U.S. at 150;

Daubert, 509 U.S. at 593. Rather, the

applicability of the various Daubert factors

depends on the particular facts and circumstances

of each case. See Kumho, 526 U.S. at 150;

Daubert, 509 U.S. at 591.

 The government argues that the district court

properly understood the analytical framework of

Daubert, and demonstrated that it was applying

the proper standard, when it stated, "I will

allow . . . the agent to proceed, one, assuming

that he will be qualified as an expert, and then,

two, into relevant inquiry." We agree that this

reflects the district court’s understanding that

in order to be qualified, an expert witness’s

testimony must be both reliable and relevant.

Furthermore, after the government laid a proper

foundation for Agent Reagan’s testimony, the

district court explicitly indicated that he was

qualified as an expert witness and the defendants

failed to object to that finding. It is wellsettled that the methods and structure of

narcotics trafficking is a proper source of

expert testimony. See United States v. Mancillas,

183 F.3d 682, 704-06 (7th Cir. 1999); United

States v. Navarro, 90 F.3d 1245, 1261 (7th Cir.
1996) ("Law enforcement officers . . . may

qualify as experts in narcotics trafficking and

may offer explanations to the jury."); United

States v. Lipscomb, 14 F.3d 1236, 1239-43 (7th

Cir. 1994); United States v. Brown, 7 F.3d 648,

652 (7th Cir. 1993) (collecting cases); United

States v. Foster, 939 F.2d 445, 451 (7th Cir.

1991); United States v. Solis, 923 F.2d 548, 550-

51 (7th Cir. 1991). It is also clear from his

experience that Agent Reagan was qualified to

offer testimony as to the general structure of

drug organizations and that his testimony

regarding drug trafficking was helpful to the

jury. Under these circumstances, we are satisfied

that the district court properly applied the

Daubert framework in considering the testimony of

Agent Reagan. Defendant Trevino’s general

objections to the testimony of Agent Reagan are

therefore unavailing.

 Defendant Trevino’s more specific objection to

Agent Reagan’s testimony does not focus on his

qualifications in general, but rather on what the

defendant characterizes as testimony about the

nature and characteristics of Hispanic drug

dealers. According to defendant Trevino, this

kind of testimony is problematic for two reasons.

First, defendant Trevino argues that Agent Reagan

was not qualified to testify about Hispanic drug

organizations because his relevant investigative

experience did not center on Hispanics or on

Hispanic areas. Second, defendant Trevino argues

that Agent Reagan’s testimony about Hispanic drug

dealers improperly introduced ethnicity into the

trial and should not have been admitted because

it was too prejudicial. While we recognize that

testimony about the relevant characteristics of

particular ethnic groups could be problematic,

and we agree that Agent Reagan’s experience did

not qualify him to speak authoritatively on the

particular characteristics of Hispanic drug

trafficking organizations, defendant Trevino’s

argument as to the nature of Agent Reagan’s

testimony is not supported by the record. 

 Agent Reagan’s testimony centered on drug

trafficking operations generally and he drew no

distinctions between Hispanic drug traffickers

and drug traffickers of any other race or ethnic

origin. In fact, Agent Reagan’s only reference to

Hispanic drug dealers during the entire course of

his testimony was an acknowledgment that in the

past he had investigated Hispanic drug

trafficking organizations. Nothing about Agent

Reagan’s testimony indicates an ethnically-based

evaluation of the evidence, nor was there any

attempt by Agent Reagan or the government to

interject the potentially prejudicial issue of

ethnicity into the witness’s testimony.

Accordingly, we find no error in the district
court’s decision to qualify Agent Reagan as an

expert and to admit his testimony regarding drug

trafficking organizations.

2. The Alleged Suppression of Impeachment

Evidence

 Defendant Trevino next challenges the failure of

the government to turn over impeachment evidence

concerning Daniel Chavez. Chavez was an informant

who testified during the government’s case-inchief regarding defendant Trevino’s involvement

in drug trafficking activities. Although Chavez

admitted on cross-examination that he had been

paid money by the government for his services as

an informant, the records of these payments were

never tendered to the defense. Defendant Trevino

contends that these government payments to Chavez

constitute impeachment evidence of an important

government witness demonstrating bias and that,

because of the nature of that evidence, the

government had an obligation to inform the

defense of the payments and to turn over any

records regarding those payments to defendant

Trevino.

 The government has an obligation to disclose

evidence favorable to the defendant upon request

when such evidence is material to the defendant’s

guilt or innocence, see Brady v. Maryland, 373

U.S. 83, 87 (1963), and that obligation extends

to both impeachment and exculpatory evidence, see

United States v. Bagley, 473 U.S. 667, 676 (1985)

(citing Giglio v. United States, 405 U.S. 150,

154 (1972)). In this case, the government argues

that it was not required to give defendant

Trevino information about the payments made to

Chavez because those payments were not relevant

to the instant case. More specifically, the

government contends that the district court judge

previously assigned to this case determined that

the payments made to Chavez were unconnected to

the government’s investigation of these

particular defendants and that this ruling

affirmatively relieved it of its obligation to

turn the disputed evidence over to the defense.

In order to evaluate this argument, we must

consider the somewhat unusual events surrounding

the determination that the payments made to

Chavez were not relevant to this case.

 The evidence regarding the government’s payments

to Chavez was first presented by DEA agents in an

in camera hearing to Judge Baker, the district

judge previously assigned to this case. This

hearing took place outside the presence of

defense counsel and there is no indication in the

record as to what was discussed during this

meeting or as to what information was provided to

Judge Baker. The record does reflect that
following this meeting, Judge Baker issued an

order stating that evidence of the government’s

payments to Chavez was inadmissible at the

defendants’ trial based on the court’s conclusion

that the payments made to Chavez were related to

a wholly separate DEA investigation. The district

court accepted Judge Baker’s determination that

the disputed evidence was irrelevant, and the

government now argues that Judge Baker’s ruling

as to this potentially impeaching evidence

relieved it of its obligation under Brady to turn

the requested impeachment evidence over to the

defense. 

 We agree with the government that no Brady

violation occurred here. The information

regarding evidence of the government’s payments

to Chavez was provided to Judge Baker and it was

determined to be irrelevant. Because the

government is only required to turn over

requested information if it is material to an

issue at trial, see Brady, 373 U.S. at 87; United

States v. Hartbarger, 148 F.3d 777, 786 (7th Cir.

1998), the district court’s determination that

the requested evidence was irrelevant necessarily

relieved the government of its obligation to turn

over information concerning Chavez’s dealings

with the government because irrelevant evidence

cannot be material. Put another way, the central

Brady inquiry on appeal is whether there is a

reasonable probability that the disputed evidence

would have affected the result at trial, see

Bagley, 473 U.S. at 682; United States v. Dimas,

3 F.3d 1015, 1018 (7th Cir. 1993), and we cannot

say that there is a reasonable probability that

evidence properly found to be irrelevant would

have affected the jury’s conclusions. The

question then is not whether the government

violated its Brady obligation when it refused to

turn over the information regarding its payments

to Chavez that had been deemed irrelevant by

Judge Baker, but rather whether the district

court erred in making its initial materiality

determination as to the disputed evidence. We

review the district court’s determination that

the disputed evidence was not material under

Brady for an abuse of discretion. See United

States v. Kozinski, 16 F.3d 795, 818 (7th Cir.

1994). 

 In circumstances where the defense seeks access

to confidential information during discovery, "we

rely particularly heavily on the sound discretion

of the trial judge to protect the rights of the

accused as well as [those of] the government."

United States v. Phillips, 854 F.2d 273, 277 (7th

Cir. 1988) ("Generally, the decisions whether to

conduct an in camera review of government files

in appropriate cases, whether to require

discovery of materials contained therein, and in
what form such materials should be produced are

committed to the sound discretion of the district

judge."). While we recognize this broad grant of

authority to district judges,/1 it is impossible

for us to determine on the record as it now

stands whether the district court properly

exercised its discretion in refusing defense

requests to turn over information regarding the

payments to Chavez. There is no information in

the record as to the substance of the meeting

between Judge Baker and the DEA agents, nor is

there any information supporting Judge Baker’s

determination that the disputed evidence was

irrelevant. Judge Baker’s docket order deeming

the evidence irrelevant, coupled with the

district court’s decision to rely on that

previous finding, do not provide a sufficient

basis for evaluating the district court’s

decision to deny defendant Trevino discovery of

the disputed information.

 Despite our conclusion that the district court

did not provide a sufficient explanation of its

decision to exclude records of the government

payments to Chavez, defendant Trevino has not

convinced us that the disputed evidence was

material. See United States v. Hamilton, 107 F.3d

499, 510 (7th Cir. 1997) (citing United States v.

Agurs, 427 U.S. 97, 109-10 (1976)) ("[A] Brady

violation does not arise due to nothing more than

a possibility that the undisclosed item might

have helped the defense . . . ."). In order to

demonstrate materiality, defendant Trevino must

show both an abuse of discretion and prejudice.

See United States v. Salerno, 108 F.3d 730, 743

(7th Cir. 1997) (quoting United States v.

Alvarez, 987 F.2d 77, 85 (1st Cir. 1993))

(stating that discovery violations warrant a new

trial only when both an abuse of discretion and

prejudice are shown); see also United States v.

Miller, 199 F.3d 416, 421 n.3 (7th Cir. 1999). In

this context, prejudice means a showing that

because of the absence of the sought-after

evidence, defendant Trevino did not "receive[ ]

a fair trial resulting in a verdict worthy of

confidence." United States v. Asher, 178 F.3d

486, 496 (7th Cir. 1999) (citing Kyles v.

Whitley, 514 U.S. 419, 434 (1995)); see Pickens

v. Runyon, 128 F.3d 1151, 1155 (7th Cir. 1997).

Prejudice exists when the defendant "is unduly

surprised and lacks an adequate opportunity to

prepare a defense, or when the violation

substantially influences the jury." United States

v. De La Rosa, 196 F.3d 712, 716 (7th Cir. 1999).

 During cross-examination, the district court

allowed the defendants to inquire into Chavez’s

work as a government informant, and Chavez

admitted that he had been paid for his services.

Although defendant Trevino admits that he was
able to question Chavez about the fact of

government payments, he contends that he was not

able to explore sufficiently the nature, and

specifically the amounts, of the payments made to

Chavez without access to the records of those

payments. Under these circumstances, however,

defendant Trevino has not shown that the district

court’s refusal to allow additional inquiry into

the government payments received by Chavez

resulted in an unfair trial, or that the evidence

he sought to obtain discovery of was anything

more than cumulative impeachment evidence. See

United States v. Maloney, 71 F.3d 645, 653 (7th

Cir. 1995) (citing Kozinski, 16 F.3d at 819)

(stating that in order to justify a new trial,

impeachment evidence "must be more than mere

cumulative impeachment"); United States v. Dweck,

913 F.2d 365, 371 (7th Cir. 1990). Because

defendant Trevino has failed to show that he was

prejudiced by the government’s failure to turn

over records regarding the government payments to

Chavez, we will not disturb the ruling of the

district court below. 

3. Sentencing Issues

 Defendant Trevino next argues that the district

court erroneously failed to grant him downward

departures based on his age, family

circumstances, and the hardship faced by his

family because of his status as an illegal alien.

Although defendant Trevino failed to request such

downward departures before the sentencing court,

he now argues that this Court may nevertheless

review his claims under a plain error standard.

Defendant Trevino also alleges that his failure

to request these departures resulted from the

ineffective assistance of his trial counsel and

he argues that this Court should consider that

claim on appeal as well.

 We find both of defendant Trevino’s sentencing

arguments to be meritless. A district court’s

decision not to depart downward is reviewable on

appeal only if the district court’s conclusion is

based on a legal interpretation of the Sentencing

Guidelines. See United States v. Ekeland, 174

F.3d 902, 905 (7th Cir. 1999); United States v.

Poff, 926 F.2d 588, 591 (7th Cir. 1991). On

appeal, defendant Trevino does not challenge the

district court’s legal conclusions, nor is there

any indication that the district court did not

believe it had the discretion to depart. Rather,

defendant Trevino challenges the district court’s

factual findings and its discretionary decision

not to depart. Such challenges are not subject to

appellate review, even in circumstances where a

motion for departure has been made before the

district court, and we therefore do not have

jurisdiction to consider defendant Trevino’s
arguments as to the district court’s failure to

depart downward. See United States v. Williams,

198 F.3d 988, 994-95 (7th Cir. 1999) ("[A]

district court’s discretionary decisions

concerning upward or downward departures are not

reviewable by this Court."); United States v.

Helton, 975 F.2d 430, 434 (7th Cir. 1992).

 In order to prevail on his ineffective

assistance of counsel claim,/2 defendant Trevino

must demonstrate both that his attorney’s

performance was objectively unreasonable and that

he was prejudiced by that performance. See United

States v. Partee, 31 F.3d 529, 534 (7th Cir.

1994). According to defendant Trevino, he has

made the necessary performance and prejudice

showings through proof that his trial counsel

failed to move for the applicable downward

departures without any strategic justification.

Although the appellate record clearly reflects

that defendant Trevino’s trial counsel did not

ask for the downward departures that defendant

Trevino now claims should have been requested,

the record does not reveal the circumstances

surrounding that decision or the strategic

concerns that may have motivated it. See United

States v. Johnson-Wilder, 29 F.3d 1100, 1104 (7th

Cir. 1994) (noting that ineffective assistance

claims should almost never be brought on direct

appeal because "typically the trial record will

be silent about the reasons for actions taken by

trial counsel"). Absent a showing that trial

counsel chose not to ask for an obviously

applicable departure without any justification

for his actions, we cannot conclude that his

performance was objectively unreasonable. We

therefore reject defendant Trevino’s ineffective

assistance of counsel claim. 

B. Defendant Joseph L. Cuevas

 The appeal of defendant Joseph L. Cuevas

focuses on the testimony of Pablo Villamil, a

rebuttal witness called by the government.

Villamil testified that he participated in a

"drug run" with defendant Cuevas, and that as

part of this venture he accompanied defendant

Cuevas and Emilio Guizar on a May 20, 1997 flight

from Chicago to Dallas. This testimony was

particularly damaging to defendant Cuevas because

Villamil was called to refute the innocent

explanation defendant Cuevas gave for that trip.

In addition, Villamil rebutted defendant Cuevas’s

statement that he and Guizar traveled alone to

Dallas on the flight in question. The government

further attempted to damage defendant Cuevas’s

credibility by introducing flight manifests

showing that, despite defendant Cuevas’s

assertion to the contrary, defendant Cuevas,

Guizar, and Villamil were all on a Vanguard

Airlines flight from Chicago to Dallas on May 20,
1997. We review the district court’s decision to

admit rebuttal testimony for an abuse of

discretion. See Spesco, Inc. v. General Elec.

Co., 719 F.2d 233, 239-40 (7th Cir. 1983).

 Defendant Cuevas’s allegations of error in

regard to the testimony of Villamil focus on what

he regards as the unfair surprise created when

the government called Villamil in rebuttal after

having failed to offer him as a witness in its

case-in-chief. It is well-established, however,

that there is no constitutional right to

discovery in non-capital criminal cases and that

the prosecution has no constitutional obligation

to reveal its witnesses prior to trial. See

Weatherford v. Bursey, 429 U.S. 545, 559 (1977);

United States v. Agyemang, 876 F.2d 1264, 1270

(7th Cir. 1989). More significantly, there is no

allegation that the government failed to comply

with any discovery rule in not disclosing the

possibility that Villamil would testify as a

rebuttal witness. See, e.g., United States v.

Braxton, 877 F.2d 556, 560 (7th Cir. 1989).

Villamil’s testimony only became necessary when

defendant Cuevas denied having been accompanied

to Dallas by Villamil, and the government was

entitled to call Villamil to rebut that testimony

and to attack defendant Cuevas’s credibility. See

United States v. O’Brien, 119 F.3d 523, 530 (7th

Cir. 1997) ("Once a defendant takes the stand and

denies his criminal activity, it is proper for

the district judge to permit the Government to

offer rebuttal evidence in contradiction of that

testimony."). Because the government had no legal

duty to disclose the identity of its potential

rebuttal witnesses, and because defendant Cuevas

put his credibility at issue by testifying in his

own defense, the district court properly allowed

Villamil to testify.

 Although precedent establishes that the

government was not required to disclose the

identity of Villamil as a rebuttal witness, the

government’s failure to turn over the Vanguard

Airlines passenger list is more problematic. This

case was conducted under an open discovery

policy, and the government was clearly obligated

to disclose the passenger list to the defense as

soon as it was received. The government did not

comply with this obligation, nor did it offer any

valid justification for this failure before the

district court or on appeal. These kind of

discovery violations are troubling in any

context, but particularly so when they are

committed by the government during a criminal

trial. However, it is significant that the

district court properly recognized the

government’s error and prohibited the government

from using the airline passenger list to rebut

defendant Cuevas’s testimony or to corroborate
Villamil’s testimony. District courts are

generally given discretion to fashion remedies

for discovery violations, see Fed.R.Crim.P.

16(d)(2), and we will not second-guess that

decision absent a showing that, on the particular

facts of this case, the district court abused

that discretion. See United States v. Beverly,

913 F.2d 337, 355 (7th Cir. 1990); see also

Taylor v. Illinois, 484 U.S. 400 (1988).

 A new trial is warranted for a discovery

violation only if "’the remedy offered by the

district court was inadequate to provide [the

defendant] with a fair trial.’" United States v.

Jackson, 51 F.3d 646, 651 (7th Cir. 1995)

(quoting United States v. Mounts, 35 F.3d 1208,

1217 (7th Cir. 1994)). In this case, defendant

Cuevas argues that the district court’s decision

to exclude the airline passenger list, but to

permit Villamil to testify on rebuttal, was

inadequate to ensure that he was provided a fair

trial. Defendant Cueveas contends that the

government acted in bad faith and intentionally

withheld the airline passenger list in order to

conceal the possibility that Villamil might

testify and that this act of deception

fundamentally altered his trial strategy.

Defendant Cuevas also argues that the district

court erred in not granting his request for a

continuance so that he could more adequately

prepare for the testimony of this surprise

witness.

 As we have previously discussed, we do not

believe that the district court abused its

discretion in its management of the discovery

issues when those issues are examined in

isolation. The district court properly permitted

the government to call Villamil as a witness, and

the district court exercised its discretion to

remedy discovery abuses by excluding the airline

passenger list that was not tendered to the

defense. Because neither of these decisions

constitute error when examined separately,

defendant Cuevas’s claim relies on a link between

the failure of the defense to provide the airline

passenger list and the detriment he suffered when

Villamil was called as a rebuttal witness to

attack his credibility. According to defendant

Cuevas, had he properly received the airline

passenger list from the government, he would have

known of the possibility that Villamil would be

called to testify and would have altered his

trial strategy accordingly (presumably by not

testifying himself or by admitting Villamil’s

presence on the May 20, 1997 flight)./3 Under

this theory, the only adequate remedy for the

government’s failure to disclose the existence of

the airline passenger list would have been to

exclude both the list itself and the rebuttal
testimony of Villamil.

 Although we reiterate our concern about the

government’s failure to turn over the airline

passenger list to the defense, we do not believe

that the district court erred in fashioning a

remedy for that violation. The passenger list

would have shown that the government was aware of

the passengers on the May 20, 1997 flight to

Dallas, but it would not have given Cuevas any

indication that Villamil was prepared to testify

that he accompanied Cuevas to Dallas. The notion

that mere possession of the airline passenger

list would have led to the conclusion that

Villamil would be called to testify and that this

realization would have altered Cuevas’s trial

strategy is too speculative to demonstrate that

the district court should have excluded

Villamil’s testimony or that defendant Cuevas was

prejudiced by the government’s actions. See

United States v. Salerno, 108 F.3d 730, 748 (7th

Cir. 1997) (quoting United States v. Alvarez, 987

F.2d 77, 85 (1st Cir. 1993)). In the absence of

a more concrete showing that disclosure of the

airline passenger list would have impacted

defendant Cuevas’s trial strategy, or some

evidence that the government acted in bad faith

in withholding that information, we cannot say

that the district court abused its discretion in

choosing to remedy the government’s discovery

violation through exclusion of the undisclosed

evidence. 

 In addition to his arguments concerning the

district court’s failure to adequately remedy the

discovery violation committed by the government,

defendant Cuevas also contends that the district

court erred when it refused to grant him a

continuance to prepare for Villamil’s testimony.

While we agree that the district court had the

discretion to grant defendant Cuevas a

continuance, see United States v. United Pacific

Ins. Co., 427 F.2d 366, 373 (7th Cir. 1970)

("[A]n application for a continuance is addressed

to the sound discretion of the trial court . . .

."), we do not believe that defendant Cuevas has

demonstrated that a continuance was mandated by

the circumstances of this case or that the

district court abused its discretion in refusing

to grant one. See United States v. $94,000.00 in

United States Currency, 2 F.3d 778, 787 (7th Cir.

1992) ("We review the trial court’s denial of a

continuance for abuse of discretion."). We base

this conclusion primarily on defendant Cuevas’s

failure to show that a continuance was necessary

in order for him to prepare for Villamil’s

testimony and on his inability to demonstrate

that the government’s actions in calling Villamil

as a rebuttal witness prejudiced his defense. See

United States v. Avery, 208 F.3d 597, 602 (7th
Cir. 2000). 

 Before Villamil was allowed to testify, the

district court ensured that defendant Cuevas was

able to interview him, and the record reflects

that defendant Cuevas had ample opportunity at

trial to cross-examine Villamil on both his

credibility and his motive for testifying.

Although defendant Cuevas now says that had he

known of the possibility that Villamil would be

called to testify he would have sought additional

information in preparation for that testimony--

including taking pictures of the Vanguard

airlines ticket counter in Chicago, investigating

the airline’s boarding and ticketing procedures,

taking pictures at the Dallas airport,

investigating rental car procedures in Dallas,

investigating bus routes from Dallas to Chicago,

ascertaining whether there was a record of a bus

ticket for Villamil, and investigating Villamil’s

employment--defendant Cuevas does not indicate

how this additional information would have aided

his cross-examination of Villamil. Moreover, much

of the further investigation sought by defendant

Cuevas involved places and events already known

and relevant to the defense’s case even before

Villamil became involved. Against this backdrop,

we cannot conclude that the district court abused

its discretion in refusing defendant Cuevas’s

request for a continuance. See Pfeil v. Rogers,

757 F.2d 850, 856 (7th Cir. 1985) ("Absent an

abuse of discretion, the trial court’s

determination of whether a continuance is

justified will not be interfered with by an

appellate court.").

C. Defendant Raul Cruz-Velasco

 Defendant Raul Cruz-Velasco alleges that the

district court erred in allowing the government

to present a revised written transcript of a

tape-recorded conversation between defendant

Cruz-Velasco and government informant Jose

Villanueva. The original transcript of this

conversation was turned over to the defense well

in advance of trial as part of discovery, but on

the eve of trial the government provided the

defense with a revised version of that

transcript. Although the government contends that

the revised transcript only contained

translations of portions previously thought

inaudible, defendant Cruz-Velasco argues that the

modifications made to the transcript were

significantly prejudicial to his defense and

justify overturning his conviction. According to

defendant Cruz-Velasco, the government’s delay in

providing up-to-date transcripts should have

resulted in a prohibition on the use at trial of

the newly-provided transcripts.
 Although this issue again raises general

problems regarding the ability of defendant CruzVelasco to react to evidence turned over late in

the discovery process, our concerns in that

regard are alleviated upon an examination of the

circumstances surrounding the revised transcript.

The delay in turning over the modified

translations was not due to the fault of the

government, but rather to the inability of the

government to review the accuracy of the original

transcript with the relevant witnesses until

shortly before trial. Apart from the transcript

itself, the defense was provided a copy of the

actual tape-recorded conversation and had ample

opportunity to seek its own translation.

Furthermore, upon hearing that the government

provided new transcripts near the start of trial,

the district court gave defendant Cruz-Velasco

the opportunity to cross-examine the government’s

expert witness on the modifications to the

transcript and informed defendant Cruz-Velasco

that he would be permitted to call his own expert

challenging the government’s version of the

translated conversation. When a defendant is

given both the time and the opportunity to

address any problems created by a new transcript

and to present an alternate version, the district

court’s refusal to exclude the new translation is

not an abuse of discretion. See United States v.

Zambrana, 864 F.2d 494, 497-98 (7th Cir. 1988)

("’Because the [defendant] had ample opportunity

to either challenge specific portions of the

government’s transcript or to prepare an

alternate version,’ he cannot now complain on

appeal when he failed to pursue those avenues at

trial.") (quoting United States v. Zambrana, 841

F.2d 1320, 1335 (7th Cir. 1988)); United States

v. Llinas, 603 F.2d 506 (5th Cir. 1979).

III. Conclusion

 Having reviewed the issues arising from the

defendants’ convictions and sentences and finding

no reversible error, we AFFIRM the decisions of the

district court.

/1 Defendant Trevino also contends that the district

court’s failure to order discovery on the

information regarding government payments to

Chavez, as well as the court’s refusal to allow

the defendants to pursue a detailed inquiry as to

the nature and source of the payments on crossexamination, violated his Sixth Amendment right

to confront the witnesses against him. It is true

that defendant Trevino has a right to confront

the witnesses against him, but that right is not

unlimited. See United States v. Rainone, 32 F.3d

1203, 1207 (7th Cir. 1994). The trial court

retains broad discretion to limit cross-
examination, see United States v. Valles, 41 F.3d

355, 359 (7th Cir. 1994), and the district court

properly exercised that discretion in this case.

Because defendant Trevino was able to adequately

question Chavez as to the fact of the government

payments, the district court’s refusal to allow

more detailed questioning on that subject does

not constitute a denial of defendant Trevino’s

Sixth Amendment rights.

/2 Although ineffective assistance of counsel claims

may be considered as a part of this appeal, we

have consistently recognized that this type of

claim is disfavored on direct review. See United

States v. Cooke, 110 F.3d 1288, 1299 (7th Cir.

1997) ("This Court’s reluctance to consider

ineffective assistance claims on direct appeal

stems, of course, from the fact that such claims

are very unlikely to find any factual support in

the trial record and an adverse determination on

direct appeal will be res judicata in any

subsequent collateral attack."); see also United

States v. Garrett, 90 F.3d 210, 214 (7th Cir.

1996); United States v. Walls, 80 F.3d 238, 243

(7th Cir. 1996).

/3 Defendant Cuevas attempts to establish that the

district court’s remedy for the government’s

discovery violation was inadequate by linking the

government’s failure to disclose the airline

passenger list to the detriment defendant Cuevas

suffered when Villamil was permitted to testify

as a rebuttal witness. In this regard, it is

significant to note that the government’s

nondisclosure of the airline passenger list and

the government’s decision to call Villamil as a

rebuttal witness were argued as separate and

distinct issues before the district court. It is

only on appeal that defendant Cuevas connects

these issues in an attempt to demonstrate

prejudice.

 Williams, Circuit Judge, dissenting in part. I

dissent from the majority opinion in two

respects.

 First, unlike my colleagues, I do not believe

that the district court adequately remedied the

government’s discovery violation. I agree that

the district court has the discretion to

determine the appropriate sanction for a Federal
Rule of Criminal Procedure 16/1 violation and

that this court will not disturb the district

court’s ruling absent a showing of unremedied

prejudice. "A defendant is prejudiced under Rule

16 only when he is unduly surprised and lacks an

adequate opportunity to prepare a defense, or

when the violation substantially influences the

jury." United States v. De La Rosa, 196 F.3d 712,

716 (7th Cir. 1999).

 The question here is whether the loss of a

potential defense strategy as the result of a

discovery violation creates enough prejudice to

require a new trial. This is an issue of first

impression for our circuit. In a similar case

from the Eleventh Circuit, the defendant

challenged his conviction on the ground that the

district court admitted into evidence a tape

recording of the defendant on rebuttal even

though the government had failed to turn over the

tape during pretrial discovery. See United States

v. Noe, 821 F.2d 604, 607 (11th Cir. 1987). In

response, the government suggested that it could

withhold discoverable inculpatory evidence until

the defendant asserted a defense strategy based

on the apparent nonexistence of that evidence,

thus foreclosing other, possibly viable, defense

strategies. See id. at 608. The Eleventh Circuit

refused to adopt the government’s suggestion

because "it would encourage precisely the ’trial

by ambush’ that the Federal Rules of Criminal

Procedure were designed to prevent." Id.

Consequently, the Noe court granted the defendant

a new trial. See id. at 609.

 In the case at bar, the government claims that

a defendant simply does not have the right to lie

under oath with impunity on the belief that the

government will not be able to prove otherwise

because he has not been given prior notice of a

rebuttal witness’ identity. The government,

however, misses the point. The issue here is

about a fair trial, not Cuevas’s credibility. The

Noe court addressed a similar argument.

 The government’s appeals to "justice" to uphold

Noe’s guilty verdicts are misplaced. Although Noe

certainly does not have the right to "fabricate"

an alibi story, the Federal Rules of Criminal

Procedure provide him a right . . . to devise a

defense strategy on the basis of the evidence

disclosed. . . . Had the government . . .

complied fully with Noe’s discovery request . .

., it would not now be before this court invoking

vague notions of justice. Likewise, had Noe been

aware of the tape recordings prior to trial, his

counsel "might well have advised [him] not to

take the stand." United States v. Padrone, 406

F.2d 560, 561 (2d Cir. 1969). The government,

however, failed to comply with Noe’s discovery
request and did not disclose the tape recording

until after Noe had developed and implemented his

trial strategy. Consequently, the government

cannot now claim that the discovery violation was

harmless.

Id. (emphasis added).

 In our case, the district court’s sanctions

were insufficient in my view. A new trial is

warranted when the failure to disclose "is so

serious a detriment to the preparation for trial

and the defense of serious criminal charges [and]

where it is apparent, as here, that [the

defendant’s] defense strategy may have been

determined by the failure to comply." Padrone,

406 F.2d at 561. The government does not provide

any valid reasons for not disclosing the airline

report and appears to have acted in bad faith.

Moreover, Cuevas’s trial strategy was

significantly prejudiced by the "ambush." See

United States v. Camargo-Vergara, 57 F.3d 993,

998-99 (11th Cir. 1995) (finding that the

government substantially prejudiced the

defendant’s case by its failure to disclose a

portion of the defendant’s statement until after

trial started because defendant had already

prepared and committed himself to a trial

strategy).

 While the majority urges us to look at the

airline manifest and Villamil’s testimony in

isolation, I do not believe that we can. The

government apparently learned of Villamil’s

identity through the subpoenaed manifest.

Consequently, he would not have been a rebuttal

witness without the government’s review of that

manifest. Because the government’s rebuttal case

was built upon knowledge gained from those

records, the banned records were "just as

effective as if [they] had been introduced in

evidence." United States v. Rodriguez, 799 F.2d

649, 654 (11th Cir. 1986). Villamil’s testimony

was especially damning. He was the only "inside"

government witness to claim that he met and dealt

with Cuevas during the alleged conspiracy. 

 If the government had timely turned over the

airline flight manifest or ticket records--the

government received these documents on the first

day of trial, Cuevas may have exercised his

constitutional right not to testify. At a

minimum, Cuevas should have had an opportunity to

properly investigate and prepare a crossexamination strategy.

 I also dissent from my colleagues’ conclusion

regarding the suppression of impeachment evidence

concerning Daniel Chavez. I do agree that the

government did not commit a Brady violation and
that the central question here is whether the

district court erred in making its initial

materiality determination as to the disputed

evidence. I am, however, troubled by the unusual

events surrounding the determination that the

payments made to Chavez were not relevant to this

case.

 Ordinarily, we rely on the sound discretion of

the district judge whether to conduct an in

camera review of government files. See United

States v. Phillips, 854 F.2d 273, 277 (7th Cir.

1988). Here we cannot, however, determine on the

record whether the district court properly

exercised its discretion. Unlike the situation in

Phillips, no record or transcript was prepared of

the ex parte in camera hearing between the

district judge and the government officials./2

Furthermore, all we have is the district judge’s

conclusory opinion that the payments made to

Chavez were related to a separate investigation.

 A jury is entitled to know all the details of a

witness’ relationship to the government. See

United States v. Muscarella, 585 F.2d 242, 248

(7th Cir. 1978); cf. United States v. Boyd, 55

F.3d 239, 245-46 (7th Cir. 1995) (ruling that

testimony in exchange for special favors to a

witness by the government or favorable treatment

in the criminal justice system should be

disclosed as impeachment evidence). This

information includes the informant’s relationship

with the government outside of the particular

case at issue. See United States v. Williams, 954

F.2d 668, 671-72 (11th Cir. 1992). "The jury has

the right to know what may be motivating a

witness, especially a government paid, regularly

employed, informant-witness." Id. at 672. 

 There may indeed be some unique circumstances

where a district court within its discretion

excludes some of this evidence as irrelevant.

However, the district judge should, at the very

least, provide the appellate court with a record-

-even if sealed--to review. By not establishing

a record, the district court effectively

nullifies appellate review. See United States v.

Southard, 700 F.2d 1, 11 (1st Cir. 1983).

Consequently, I believe that the court below

abused its discretion.

 My colleagues conclude that the defendants were

not prejudiced because the error, if any, was

harmless. Chavez admitted on cross-examination

that he was a paid government informant.

Therefore, the majority finds that any other

evidence of payments would have been merely

cumulative. Because the record is incomplete,

however, I do not believe that we can make that

determination. Furthermore, Chavez was an
important government witness who detailed drug

deals and other illegal activities among the coconspirators. His testimony may very well have

been effectively impeached if the jury knew his

complete relationship to the prosecution.

 Therefore, I respectfully dissent on these two

issues.

/1 Fed. R. Crim. P. 16(a)(1)(C) requires discovery

of certain documents, including those that are

"material to the preparation of the defendant’s

defense."

/2 In Phillips, the appellate court was able to

review the entire file that the district court

had viewed in camera. 854 F.2d at 277.