* Pursuant to 5 TH C IR

. R. 47.5, the Court has determine d that

this opinion should not be published and is not precedent except

under the limited circumstances set forth in 5 TH C IR

. R. 47.5.4.

IN THE UNITED STATES COURT OF APPEALS

FOR THE FIFTH CIRCUIT

___________________

No. 96-20149

Summary Calendar

UNITED STATES OF AMERICA,

Plaintiff-Appellee,

versus

CESAR JAVIER GARCIA, also known

as Cowboy,

Defendant-Appellant.

________________________________________________

Appeal from the United States District Court for the

Southern District of Texas

(CR-H-94-288-1)

________________________________________________ July 15, 1997

Before GARWOOD, DeMOSS and STEWART, Circuit Judges. *

GARWOOD, Circuit Judge:

Defendant-appellant Cesar Javier Garcia (Garcia) appeals his

conviction and sentence for conspiracy t o possess with intent to

distri bute more than one hundred kilograms of marihuana. We

affirm.

Facts and Proceedings Below1 In exchange for Mata’s assistance, the State agreed to dismiss

Mata’s pending ma rihuana charge and agreed not to revoke his

parole. Also, prior to Garcia’s trial, the State paid Mata’s

relocation expenses totaling approximately $3,500.

2 On February 3, 1994, Alex Mata (Mata) entered into a written

agreement with the Harris County District Attorney’s Office and

Houston Police Department (State) whereby Mata——who had a criminal

history and had pending at the time a stat e felony charge for

delivery of marihuana——agreed to assist the State with the arrest

and charging of Garcia for aggravated robbery or conspiracy to

commit aggravated robbery. 1 To accomplish this goal, the State

along with federal authorities set up a “sting” operation in which

Mata would play the role of a middleman between Garcia (the buyer)

and Crisanto Perez (Perez), an undercover special agent w ith the

Bureau of Alcohol, Tobacco, and Firearms who posed as a marihuana

seller from the Rio Grand Valley in South Texas. The plan called

for Garcia and Mata to arrange a sham marihuana buy with Perez so

that Garcia could find out where the marihuana was being stored,

allowing him to steal the drugs for resale.

As planned, in late April of 1994 Mata approached Garcia and

told him that Perez had 1,000 pounds of marihuana and was looking

for a potential buyer. Garcia told Mata that he was interested in

working with him and provided Mata with his telephone number and

pager number. Beginning in May of 1994, Mata began secretly

recording conversations he had with Garcia over the telephone and

in person. In these conversations, Garcia continued to express2 Mata also secretly recorded conversations he had with

Alcantar.

3 As part of the undercover operation, police officers had

placed 1,000 pounds of marihuana in a warehouse so that Alcantar

could inspect the drugs. They also set up hidden video cameras to

record the meeting and any subsequent robbery attempts.

3 interest in the sham transaction and indicated that his “compadre”

Jose Alcantar (Alcantar), also known as Joe Diamond or Diamond Joe,

would assist in the operation. 2

On June 30, 1994, Mata and Perez met with Alcantar at

Michael’s International Nightclub in the southwest area of Houston.

Also present with Alcantar at the nightclub were Garcia and several

other men. Mata went over to the table at which Alcantar, Garcia,

and others were sitting and, a short while later, returned to

Perez’s table with Alcantar. Alcantar told Perez that he was

interested in purchasing 250 pounds of marihuana, and Alcantar and

Perez agreed on a price o f $550 per pound. In accordance with

Garcia’s instructions, Alcantar then followed Perez to the

warehouse where the m arihuana was being stored so that Alcantar

c ould inspect the drugs. After testing the marihuana, Alcantar

approved of its quality and requested that t he transaction take

place the next day. 3

Over the next several days Garcia, Alcantar, and Mata remained

in contact with one another and had numerous discussions pertaining

primarily to the location of the marihuana, the amount of marihuana

that remained in the warehouse, and the timing of the robbery. At4 The individuals in the van were Robert Luis Gonzalez, Rogelio

Mata, Juan Mata, Adrian Mata, Joe Luis Lerma, and Raymond Palomo

Trevino.

5 Hidden video cameras captured the botched robbery on tape.

4 one point during this time, Mata informed Garcia that the quantity

of marihuana stored in the warehouse had increased to 1,400 pounds.

On July 20, 1994, Mata and Alcantar tried unsuccessfully to contact

Garcia. Alcantar called Mata that same day and told Mata that he

wanted to go ahead with the robbery without Garcia. Apparently,

Alcantar “said he already talked to Cesar and it was no problem

with Cesar.” In the early morning hours of July 21, 1994, Mata,

Alcantar, and several other men drove to the warehouse with the

intention of stealing the marihuana. Alcantar and two of his

cohorts , Julian Mata, Jr. and Norberto Coronado, drove in one

vehicle w h ile six other men followed in a grey van. 4 Unbeknownst

to the would-be thieves, the warehouse was then empty, as the

police had previously transported the drugs to a differ ent

location.

When they arrived at the warehouse, one of the men in the van

hooked up a steel chain to the garage door of the war ehouse and,

with the other end of the chain connected to the van, proceeded to

pull the door off the warehouse. Much to their dismay, the entire

load of marihuana was gone. As they attempted to flee, SWAT

officers swarmed the area and arrested the six men who had arrived

in the van. 5 Four weapons were seized from the van, including6 Charged in the same indictment were codefendants Alcantar,

Julian Mata, Jr., Norberto Coronado, Robert Luis Gonzalez, Rogelio

Mata, Juan Mata, Adrian Mata, Joe Luis Lerma, and Raymond Palomo

Trevino. All defendants except Garcia pleaded guilty.

5 three 9mm pistols, a .38 caliber pistol, and several rounds of

ammunition. Alcantar and the two men in his car, who had left the

area before the SWAT team arrive d, were all arrested a few days

later.

On July 24, 1994, Mata and an acquaintance were driving on a

Houston road when Garcia, who was driving his family to a shooting

range, pulled up next to Mata’s vehicle, pointed a gold-plated .45

c aliber semi-automatic pistol at Mata, and shouted a threat.

Mata’s vehicle accelerated quickly away. Mata provided the police

with a description of Garcia’s vehicle and weapon. On July 25,

1994, police office rs arrested Garcia after they spotted him

driving a veh icle that matched Mata’s description. The officers

found in the glove compartment of his car the gold-plated pistol

that Mata alleged Garcia had pointed at him.

On December 2, 1994, Garcia was cha rged by indictment with

conspiracy to possess with intent to distribute marih uana (count

one) in violation of 21 U.S.C. §§ 841(a)(1), (b)(1)(B), and 846,

and aiding and abetting the use and possession of a firearm during

and in relation to a drug trafficking offense (count two) in

violation of 18 U.S.C. § 924(c). 6 On October 19, 1995, a jury

found Garcia guilty on count one but not guilty on count two. On

February 5, 1996, Garcia was sentenced to 160 months in prison, 56

years of supervised release, and fined $5,000.

Discussion

Garcia raises numerous arguments on appeal. Specifically, he

alleges that (1) the method of selecting jurors in the Houston

Division of the Southern District of Texas systematically excludes

Hispanics; (2) the agreement between the government informant and

the State violated due process; (3) the evidence was insufficient

to support his conviction for conspiracy to possess with intent to

distribute marihuana; (4) the district court improperly instructed

the jury on his withdrawal defense; (5) the district court abused

its discretion by declini ng to instruct the jury on multiple

conspiracies; and (6) the district court erred when it calculated

the amount of marihuana attributable to him for sentencing purposes

and when it increased his offense level based on obstruction of

justice and his leadership role in the conspiracy. We address each

argument in turn below.

1. Jury Selection Process

Garcia cont ends that the method of selecting jurors in the

Houston Division of the Southern District of Texas systematically

excludes Hispanics in violation of t he Sixth Amendment to the

United States Constitution and the Jury Selection and Service Act

of 1968, 28 U.S.C. §§ 1861-1878 (Jury Act). Under the current

system employed by the Houston Division, the jury wheel from which

both grand and petit jurors are selected is generated by selecting7 In ruli ng on Garcia’s Motion to Dismiss Because of Improper

Selection of Grand and Petit Jury, the district court below adopted

the conclusions of law and find ings of fact entered in a similar

c ase, United States v. Rodriguez , Cr. No. H-94-216 (S.D. Tex.).

The parties in this case submitted all of the evidence and the

transcript of the hearing in the Rodriguez case as evidence to the

district court. In addition to the evidence from the Rodriguez

case, the court below also considered the testimony of Ray Hardy

(Hardy), a former District Clerk of Harris County who was involved

in the development of Texas’s new jury selection system, which now

includes drivers license lists. Hardy testified that the main

motivation behind this change was a perception that m any people

were purposefully avoiding jury service by choosing not to register

to vote.

7 names exclusively from voter registration lists. Garcia contends

t hat because at least 13% of the Hispanics in the Division are

eligible to serve as jurors but only 7.5% of Hispanics actually

register to vote, the current system does not produce grand and

petit juries that represent a fair cross-section of the community.

Garcia believes that the Division has available and should use a

li st of registered voters a nd licensed drivers that would,

according to Garcia, more accurately reflect the racial composition

of the Division. 7

Under both the Sixth Amendment and the Jury Act, litigants are

enti tled to have their grand and petit juries drawn from a fair

cross-section of th e community in the district or division where

the court convenes. U nited States v. McKinney

, 53 F.3d 664, 670-71

(5th Cir.), cert. denied , 116 S.Ct. 261 (1995). In order to make

a prima facie showing that his right under the Sixth Amendment to

have a jury drawn from a fair cross-section has been violated,8 In order to serve on a jury, one must be a citizen of the

United States, at least 18 years old, be able to understand, read,

speak, and write English, not suffer from a mental and physical

infirmity, and not have a charge pending against him or her or have

a conviction of a crime punishable by imprisonment of more than one

year. 28 U.S.C. § 1865(b).

8 Garcia must demonstrate that (1) the group he claims is being

excluded is a “distinctive” group within the communi ty; (2) the

group’s representation in venires from which juries are selected is

not fair and reasonable in relation to the number of such persons

in the community; and (3) this underrepresentation is c aused by

systematic exclus ion of the group in the jury selection process.

Duren v. Missouri

, 99 S.Ct. 664, 668 (1979). The distinctive group

consists of the pool of individuals in that division who are

eligible to serve as jurors and not the group’s total population in

the community. 8 United States v. Fike , 82 F.3d 1315, 1321 (5th

Cir.), cert. denied

, 117 S.Ct. 241 (1996). A trial court’s factual

d etermination that there is no systematic exclusion of mino rity

members from the venire is reviewed for clear error. U nited States

v

. Sotelo

, 97 F.3d 782, 790 (5th Cir. 1996), cert. denied

, 1 1 7

S.Ct. 1002 (1997).

In United States v. Maskeny

, 609 F.2d 183 (5th Cir.), cert.

denied , 100 S.Ct. 3010 (1980), we held that in order to determine

whether there has been a violation of the Sixth Amendment we must

look to the “absolute disparity” between the proportion of members

of an identifiable class in the community and its representation in9 Absolute disparity measures the difference between the

percentage of a distinctive group in a certain population and the

percentage of that group in a su bset of that population. In the

jury selection context, t his figure is generally achieved by

subtractin g the percentage of a group on the jury wheel from the

percentage of persons within that group who are eligible to serve

as jurors. S ee United States v. Esquivel

, 88 F.3d 722, 726 (9th

Cir.), cert. denied , 117 S.Ct. 442 (1996).

9 venires from which juries are selected. 9 I d

. at 189-90. In so

holding, we rejected the defendants’ argument that we should base

our Sixth Amendment analysis on data derived from other statistical

methods, such as comparative disparity and standard deviation. I d

.

at 190. The Court went on to conclude that because the absolute

disparity “between the percentage of each allegedly ‘distinctive’

group in the community and the percentage of that group

. . .

ending up on the qualified wheel is less than ten percent,” the

defendants did not make out a Sixth Amendment violation. I d .; see

also United States v. Butler

, 611 F.2d 1066, 1069-70 (5th Cir.),

cert. denied

, 101 S.Ct. 97 (1980). S ince Maskeny

, many other

courts have similarly held that an absolute disparity of less than

10% alone is not enou gh to demonstrate underrepresentation under

th e Sixth Amendment. S ee, e.g., United States v. Joost

, 94 F.3d

640 (tab.), No. 95-2031, 1996 WL 480215, at *8 (1s t Cir.), c ert.

denied

, 117 S.Ct. 408 (1996); United States v. Grisham

, 63 F.3d

1074, 1078-79 (11th Cir. 1995), cert. denied

, 116 S.Ct. 798 (1996);

United States v. Ashley

, 54 F.3d 311, 313-14 (7th Cir.), cert.

denied

, 116 S.Ct. 232 (1995); see also United States v. Hawkins

,10 Garcia asserts that this Court should abandon th e absolute

disparity test and should adopt either the comparative disparity

model or the disparity of risk model. Under the comparative

disparity model, which focuses on the percentage difference between

the proportion of the distinctive group eligible to serve as jurors

and the shortfall in that group’s representatio n, the disparity

would amount to approximately 42%. See United States v. Hafen

, 726

F.2d 21, 23-24 (1st Cir.), cert. denied

, 104 S.Ct. 2179 (1984).

Garcia contends that the comparative model is especially important

in situations, such as in this case, where the minority group is so

small that it would be difficult to meet the 10% minimum under the

absolute disparity model. The disparity of risk model measures the

statistical frequency of underrepresentation of the distinctive

group on juries, which in this case would be approximately 35%.

Under either of these alternative models, the dispar ity would be

substantially greater than the 4.8% dispa rity under the absolute

disparity model. See infra

.

As a threshold matter, we do not agree with Garcia’s assertion

that the comparative disparity model provides a more accurate

assessment of underrepresentation than does the absolute disparity

model. S ee Hafen

, 726 F.2d at 23-24 (explaining that “the smaller

the group is, the more comparative disparity figure distorts the

proportional representation”). Moreover, most courts have rejected

requests by litigants t o abandon the absolute disparity model in

favor of one of the alternative disparity models. S ee, e.g.,

Joost

, 1996 WL 480215, at *8; Esquivel

, 88 F.3d at 726; Ford v.

Seabold

, 841 F.2d 677, 684 & n.5 (6th Cir.), c ert. denied

, 109

S.Ct. 315 (1988); United States v. Rodriguez , 776 F.2d 1509, 1511

(11th Cir. 1985); Hafen , 726 F.2d at 23. However, even assuming,

10 661 F.2d 436, 442 (5th Cir. 1981).

We reiterated our less-than-ten-percent standard in United

States v. Butler

, 615 F.2d 685 (5th Cir. 1980) (per curiam)

(denying pet itions for rehearing and rehearing e n banc ). In

Butler , we clarified our prior panel opinion by explaining that

“[w]e did not wish to imply that the absolute disparity

method is the sole means of establishing un lawful jury

discrimination. However, given the small absolute

disparities proven and the fact that a ‘les s-than-10

percent minority’ was not at issue, we did not feel

consideration of other statistical methods was necessary

in this case.” 10 Butler , 615 F.2d at 686.arguendo

, that we considered the comparative disparity or disparity

of risk model to be superior to the absolute disparity model, we

would nevertheless be precluded from adopting either of these

alternative models today, as we are bound by Maskeny and Butler

absent a Supreme Court decision or an en banc deci sion by this

Court in dicating otherwise. S ee United States v. Pettigrew

, 77

F.3d 1500, 1511 n.1 (5th Cir. 1996).

11 Neither party opposes using the percentage of adult Hispanic

citizens as a substitute for the percentage of Hispanics eligible

to serve on juries, even though jury service requires more than

simply being an adult citizen (e.g. a degree of proficiency in

English). Also, both parties wholly adopt the data produced in

Rodriguez despite the fact that the Rodriguez case used statistical

evidence gathered on both the Houston and Galveston Divisions,

while this case only involves a challenge to the selection system

in the Houston Division.

Moreover, as discussed in footnote 9, supra

, absolute

disparity figures are generally calculated by taking the difference

of the percentage of persons within a group who are eligible to

serve as jurors and the percentage of that group on the jury wheel.

The court below, as did the district court in Rodriguez

, calculated

absolute disparity by subtracting the percentage of adult Hispanic

11 See also Rodriguez

, 776 F.2d at 1511 n.4 (stating that “[a]lthough

the absolute disparity method is not the sole means of establishing

unlawful jury discrimination, where small absolute disparities are

pro ven, as in this instance, and the minority group involved

exceeds ten percent of the population, which is also the case in

this challenge, it is not necessary to consider other statistical

methods”).

The parties do not dispute the fact that the percentage of

Hispanics eligible to serve as jurors in the Division exceeds 10%;

thus, we need only consider the absolute disparity between the

percentage of Hispanics eligible to serve on juries and the

percentage of Hispanic registered voters in the Division. 1 1citizens from t he p ercentage of Hispanic registered voters

. The

parties did not object below nor do they object on appeal to using

percentages of registered voters instead of percentages of

Hispanics on the jury wheel to determine underrepresentation. In

any event, nothing in the record indicates that the percentage of

Hispanics who register to vote is any different from the percentage

of Hispanics who appear on the jury wheel.

12 Professors A lford and Stein also found that 7.46% of the

persons called to serve on grand juries were Hispanic, 7.28% of the

persons who appeared were Hispanic, and 7.34% of the persons who

were selected were Hispanic.

13 The court decided to use the 7.6% figure because it was more

favorable to Garcia.

12 According to two of the experts who provided jury data analysis to

the district court in Rodriguez

, Professors John R. Alford and

Robert M. Stein of Rice University, 7.7% of the registered voters

in the Houston and Galveston Divisions are Hispanic, while the

percentage of Hispanic adult citizens in the same Divisions is

12.4%. 12 Another expert, Professor Kent L. Tedin of the University

of Houston, opined that the percentages o f Hispanic registered

voters and adult Hispanic citizens are closer to 7.6% and 12.8%,

respectively. The court found——and we do not consider the finding

to be clearly erroneous——that the 7.6% and 12.4% figures best

reflect the actual percentages, and concluded that th e 4.8%

disparity unequivocally demonstrates that the jury selection system

does not result in an underrepresentation of Hispanics on the jury

wheel. 1 3 Thus, because the percentage of Hispanics eligible to

serve as jurors i n the Division clearly well exceeds 10% and the

absolute disparity between the percentage of Hispanic regis tered14 Moreover, even if we were to accept Garcia’s exaggerated

figures of 7.5% and 13%, the absolute disparity would still amount

to only a 5.5% difference, far shy of th e 10% minimal disparity

needed under Maskeny and Butler

.

13 voters and the percentage of Hispanics eligible to serve on juries

is substantially less than 10%, we hold that Garcia has not made a

prima facie case of underrepresentation under the Sixth Amendment. 14

Likewise, Garcia’s Jury Act challenge also lacks merits. To

show that the method of selecting jurors in the Houston Division is

not in conformity with the requirements of the Act, Garcia must

establish that there is a substantial failure to comply with the

Act’s provisions. 28 U.S.C. § 1867. Technical violations that do

not affect the random nature or objectivity of the se lection

process do not constitute a substantial failure to comply. See

United States v. Brummitt

, 665 F.2d 521, 528 (5th Cir. 1981), cert.

denied , 102 S.Ct. 2244 (1982).

Garcia has failed to make the necessary showing. The Jury Act

itself expressly authorizes the adoption of a jury plan under which

potential jurors are selected exclusively from voter registration

lists; additional sources are only required if necessary to protect

rights secured by the statutory scheme involved. See 28 U.S.C. §

1863(b)(2). The legislative history of the Act “suggests that

Congress, rather than disapproving the element of nonrand omness

implicit in any form of self-screening, wanted people who lacked a

sense of civic obligation not to serve on federal juries, unless14

the number of ‘no-shows’ was so great that the qualified jury wheel

could not be filled up. In that event, but only in that event, the

clerks could be exp ected to use the coercive powers that the Act

gave them.” U

nited States v. Gometz

, 730 F.2d 475, 480 (7th Cir.),

cert. denied

, 105 S.Ct. 155 (1984). Hence, the “failure of an

identifiable group to register and vote does not render invalid the

selection of jurors from a voter registration list.” B rummitt

, 665

F.2d at 529; see also United States v. Apodaca

, 666 F.2d 89, 92-93

(5th Cir.), cert. denied

, 103 S.Ct. 53 (1982); United States v.

Arlt , 567 F.2d 1295, 1297 (5th Cir.), cert. denied , 98 S.Ct. 2250

(1978).

We do not consider the district court’s finding t hat the

current selection system “is advantageous because it results in the

selection of individuals over 18 years and those who are citizens

of the United States, both of which are qualifications for jury

service,” to be clearly erroneous. Additionally, “[t]he use of

voter lists as a source insures that individuals who are interested

enough in their community to register to vote will be able to serve

as jurors.” Nothing in the record compels us to conclude that the

c ourt clearly erred in its determination that the current system

“is unbiased at each of its selection points” and that “[t]he

sel ection process is racially and ethnically neutral and is not

susceptible to being used as a tool of discrimination.”

Furthermore, Garcia has not explained h ow a jury selection15

system based on both voter registration and drivers license lists

would produce a jury wheel that would be more reasonable than that

generated under the current system. Indeed, as evidenced by the

testimony of Hardy given at the pre-trial hearing, such a system

would likely be ove rly inclusive, as many people who would

otherwise qualify for a drivers license would not be eligible to

serve on juries . According to Hardy, Texas’ drivers license

s election scheme so far has proven to be largely ineffective

primarily becau se persons who have felony convictions or are not

United States citizen——qualities making them ineligible f or jury

service——routinely are included on the list used by the County

Clerk to compose the jury wheel. Conversely, with the one obvious

exception that citizens who are unable to read, write, and speak

E nglish can vote but cannot serve as jurors, the qualifications

needed to vote and to serve on juries are substantially similar.

Although arguably under certa in circumstances it may be

appropriate to supplement voter registration lists with some other

source, such as drivers license lists, in order to protect the

rights secured by the Jury Act, this is plainly not such a case.

Garcia does not allege, nor is there any evidence tending to show,

that the jury list is selected in a nonrandom manner or that there

has been any finagling at any stage of the selection process. The

district court in essence found that this was not the situation,

and nothing in the record suggests erro r in that finding. For

these reasons and the reasons stated earlier, we conclude that15 In the district court below, Garcia objected to the jury

selection process on Fifth Amendment grounds in addition to his

Sixth Amendment and Jury Act challenges. On appeal, however, he

challenges the selection process exclusively on Sixth Amendment and

Jury Act grounds. His failure to brief his Fifth Amendment

challenge constitutes a waiver of that argument. S ee Graef v.

Chemical Leaman Corp

., 106 F.3d 112, 115 n.2 (5th Cir. 1997).

However , even if we were to consider the merits of a Fifth

Amendment challenge to the jury selection process, we would

nevertheless conclude that such a claim would fail, as Garcia has

offered nothing but stat istics to support his allegations of

discrimination, and these statistics are alone insuffic ient to

support a claim of intentional discrimination under the Fifth

Amendment. S ee Brummitt , 665 F.2d at 527 (stating that “[a] prima

facie case of discrimination cannot rest merely on statistics. The

fact that an identifiable minority group votes in a proportion

low er than the rest of the population and is therefore

underrepresented on jury panels presents no constitutional issues”)

(citations omitted). Moreover, Garcia has provided no evidence of

discriminatory intent in the selection process, and we regard the

lower court’s finding that the selection process is “unbiased” and

“racially and ethnically neutral” as well supported and no t even

approaching clearly erroneous.

16 Garcia’s jury selection challenges fail on both Sixth Amendment and

Jury Act grounds. 15

2. Mata’s Agreement With the State

Garcia claims that his due process rights were violated by the

State’s use of Mata, who was an informant a nd testified as a

government witness at Garcia’s trial. Garcia insists that the

“contingency fee” agreement resulting in Mata’s testimony offended

the Due Process Clause and that the district court erred by denying

his motion to dismiss the indictment or suppress evidence gathered

by Mata. In support of his argument, Garcia relies chiefly on

Williamson v. United States

, 311 F.2d 441 (5th Cir. 1962), cert.

denied

, 85 S.Ct. 1803 (1965), in which this Court established a per16 Mata was relocated due to threats to his safety.

17 se rule that an informant paid a contingency fee is not a competent

witness.

There are numerous problems wit h Garcia’s argument. First,

Mata’s agreement was with the State of Texas, not with the federal

authorities who prosecuted Garcia. Indeed, Mata had no agreement

whatsoever with the federal government. Second, Mata’s contingency

fee agreement consisted of neither a contingency nor a fee. Under

the agreement, the State agreed not to revoke Mata’s parole, to

dismiss his marihuana charge, and to pay for relocation expenses,

which totaled approximately $3,500, in exchange for Mata’s

assistance in the successful “arrest and charging” of Garcia. 16 The

benefits of the agreement were not contingent upon the successful

prosecution of Garcia. Also, this agreement did not involve

payment of any fees as consideration for Mata’s services; rather,

the consideration was for the State to drop the felony charge and

not revoke his parole. The only fees received by Mata——the

relocation expenses——were not paid as consider ation for his

services and certainl y were not contingent upon the government’s

getting a conviction against Garcia, as evidenced by the fact that

Mata was paid prior to Garcia’s trial.

Lastly, Garcia faces one fi n al insurmountable hurdle: in

United States v. Cervantes-Pacheo

, 826 F.2d 310 (5th Cir. 1987) (en

banc), cert. denied

, 108 S.Ct. 749 (1988), we overruled Williamson

,18

holding that “the credibility of the compensated witness, like that

of the witness promised a reduced sentence, is for a properly

instructed jury to determine. Accordingly, we overrule W illiamson

and its per se exclusionary rule.” Id

. at 316. As we explained in

Cervantes-Pacheo

, an informant who is promised a contingency fee or

other benefits is not automatically excluded from tes tifying at

trial; rather, the matter should be left to the jury to consider in

weighing the cre dibility of the witness-informant. Id

. at 315.

Certain procedural safeguards, howev er, must be employed in

connection with the use of the informant’s testimony:

“The government must not use or encourage the use of

perjured testimony; the government must completely and

timely disclose the fee arrangement to the accused

. . .;

the accused must be given an adequate opportunity to

cross-examine the informant and government agents about

any agreement to compensate the witness; and the trial

court should give a special jury instruction pointing out

a suspect credibility of paid witnesses.” United States

v. Bermea

, 30 F.3d 1539, 1552 (5th Cir. 1994), cert.

denied , 115 S.Ct. 1113 (1995).

See also United S tates v. Pruneda-Gonzalez , 953 F.2d 190, 197-98

(5th Cir.), cert. denied , 112 S.Ct. 2952 (1992).

In the case sub judice

, all of these procedural saf eguards

have been satisfied. Garcia does not claim nor does the evidence

show that the government knowing ly used or encouraged perjured

testimony; the government timel y disclosed the agreement to the

defense; Garcia thoroughly cross-examined Mata at trial about his

agreement with the State; and the district court cautioned the jury19

with a special instruction (as to which no complaint is made)

concerning Mata’s suspect credibility as a compensated or immunized

government informant. Reversal is not warranted based on Mata’s

involvement in this case.

3. Sufficiency of the Evidence

Next, Garcia argues that the evidence was insufficient to

support his conviction for conspiracy. Specifically, he contends

that he had no discussions with any of his codefendants, except for

Alcantar; the only evidence of those discussions was “puffing” on

his taped calls with Mata or between Mata and Alcantar; in the days

preceding the attempted robbery, he repeatedly failed to return

calls from Ma ta and Alcantar; and he did not go with his

codefendants to the warehouse.

In considering Garcia’s sufficiency of the evidence claim, we

view the evidence presented and all inferences that may be drawn

therefrom in the light most favorable to the jury’s verdict, and

decide whether any rational trier of fact could have found each

element of the crime beyond a reasonable doubt. United States v.

Resio-Trejo

, 45 F.3d 907, 910-11 & n.6 (5th Cir. 1995). In a drug

conspiracy prosecution under 21 U.S.C. § 846, the government must

prove beyond a reasonable doubt (1) the existence of an agreement

between two or more persons to violate the narcotics laws; (2) that

the defendant knew of the agreement; and (3) that the defendant

voluntarily participated in the agreement. U nited States v.17 Other than through cross-examination of government witnesses,

the defense presented no evidence apart fro m a stipulation that

there was an outstanding arrest warrant for Mata.

20 Limones

, 8 F.3d 1004, 1009 (5th Cir. 1993), cert. denied

, 114 S.Ct.

1562 (1994); United States v. Maltos , 985 F.2d 743, 746 (5th Cir.

1992). A conspiracy can be established by circumstantial evidence,

that is, the jury frequently may infer its existence from a

defendant’s concert of action with others. U nited States v.

Cardenas

, 9 F.3d 1139, 1157 (5th Cir. 1993), cert. denied

, 114

S.Ct. 2150 (1994). The agreement and the defendant’s knowledge and

parti cipation in the conspiracy may be inferred from the

“development and collocation of circumstances.” Maltos , 985 F.2d

at 746 (internal quotations and citation omitted).

The evidence shows, primarily through taped conversations and

Mata’s testimony, that Garcia repeatedly agreed to enter into the

conspiracy to steal amounts of marihuana ranging from 1,000 to

1,400 pounds; that Garcia recruited Alcantar to assist in the scam;

that Garcia scheduled the meeting between Alcantar and the seller;

that Garcia conferred with Alcantar prior to going to the warehouse

to inspect the marihuana; and that Garcia continued to show

interest in the days immediately before the attempted robbery. 1 7

Viewing the evidence and all reasonable inferences therefrom in the

light most favorable to the verdict, we hold that there is amply

sufficient evidence for a reasonable jury to conclude that Garcia

actively participated in the conspiracy.21

4. Withdrawal Defense

Garcia next contends that the district court erred by refusing

to give a correct jury instruction on his withdrawal defense. He

complains th at the instruction given unnecessarily narrowed the

jury’s co nsideration of activities that could have constituted

withdrawal. Also, he argues that the district court erred by

denying his request that the jury be instructed that if he proved

he withdrew from the conspiracy prior to the robbery he should be

found not guilty. The actual instruction, according to Garcia,

left open the possibility that the jury could have found him guilty

even if they believed that he withdrew from the conspiracy.

We review the lower court’s refusal to give a requested jury

instruction for abuse of discretion. United States v. Branch , 91

F.3d 699, 711 (5th Cir. 1996), cert. denied

, 117 S.Ct. 1466 (1997).

We may reverse only if the requested instruction is substantially

correct, was not substantially covered in the charge as a whole,

and concerns an important point in the trial, the omission of which

materially impaired the defendant’s ability to present a given

defense effectively. U nited States v. Tan nehill , 49 F.3d 1049,

1057-58 (5th Cir.), cert. denied , 116 S.Ct. 167 (1995).

The instruction given by the court on withdrawal was a correct

statement of the law and appears to have provided an adequate basis

for the defendant to argue that he was entitled to be found not

guilty based on that defense. Further, the instruction immediately22

preceding the withdrawal instruction directed the jury that the

defendant must be a member of the conspiracy at the time that the

offense is committed in order to be responsible for the offense.

Hence, the jury was instructed that if it determined that Garcia

had withdrawn from the conspiracy at the time that the offense was

committed, it could not find him guilty of the conspiracy offense.

Furthermore, there was no evidence of withdrawal, and

certainly not of withdrawal before any overt act in furtherance of

the conspiracy. United States v. Nicoll , 664 F.2d 1308, 1315-16

(5th Cir.), cert. denied

, 102 S.Ct. 2929 (1982). The district

court did not reversibly err in refusing to give the requested

instruction.

5. Multiple Conspiracy

Garcia argues that the district court erred in not giving the

jury his requested in struction on multiple conspiracies. He

asserts that the evidence “arguably” supports the existence of two

conspiracies, the first occurring before July 20 and the second

being the July 21 attempted robbery. Garcia contends that his

requested instruction, which stated that “to prove Count One, the

prosecution must prove beyond a reasonable doubt the conspiracy

alleged in the indictment

. . . [and not a] different conspiracy,”

should have been given to the jury.

In considering whether a district court properly refused such23

a request ed jury instruction, this Court determines whether the

requested instruction was supported by the evidence. U nited States

v. Asibor

, 109 F.3d 1023, 1036 (5th Cir. 1997). In determining

whether a multiple conspiracy instruction should be given, we

cons ider “the times, places, persons, offenses charged, and the

overt acts involved.” I d

. (internal quotations and citations

omitted). The evidence shows that Garcia and Mata had several

conversations in which Garcia expressed his intent to steal the

entire load of marihuana from the warehouse, and although certain

minor details of the drug heist were unsettled, throughout the

entire conspiracy the single primary purpos e of the conspiracy

never changed. Alcantar and the other codefendants all fully

participated in this same conspiracy, a nd nothing in the record

indicates that any of these codefendants were operating under a

different conspiracy. Accordingly, the district court did not err

in refusing to give the requested instruction because the evidence

does not reflect the existence of more than one conspiracy.

6. Sentencing Challenges

Garcia’s final argument on appeal i s a challenge to his

sentence on three separate grounds. First, he argues that the

district court erred in determining the quantity of marihuana

att ributable to him, as various quantities of marihuana were

discussed during the taped conversations ranging from 200 to 1,400

pounds. He contends that he should not be held accountable for the

1,500 pounds anticipated to be obtained during the July 21 robbery24

attempt, but instead should be accountable for only 600-800 pounds.

This Court reviews a district court’s factu al findings

concerning the quan tity of drugs attributable to a defendant for

clear error. U

nited States v. Maseratti

, 1 F.3d 330, 340 (5th Cir.

1993), cert. denied , 114 S.Ct. 1096 (1994). A factual finding is

not clearly erroneous if it is plausible in light of the record of

the case as a whole. I d

. During a taped telephone conversation 2

days before the robbery, Mata told Garcia that the seller had

brought in an additional 800 pounds of marihuana and that the

seller now had 1,400 pounds of marihuana. Garcia responded that

was fine and later that evening indicated that he had everything

ready to go for the next day. Thus, there was reliable evidence in

the record to support a finding that Garcia was personally aware

that the conspiracy involved 1,400 pounds of marihuana. The 100

pound differe nce was inconsequential with respect to the

calculation of Garcia’s base offense level. S ee U.S.S.G. §

2D1.1(c)(6). That is, the same guideline range would have been

produ ced by 1,400 (or 1,000) pounds as by 1,500 pounds. The

court’s finding was not clearly erroneous.

Second, Garcia contends that the district court erred in

denying his objection t o the two-level upward adjustment for

obstruction of justice based on Mata’s allegation that on July 24,

a few days after the attempted robbery, Garcia pointed a pistol at

him and shouted a threat. Garcia asserts that he never threatened

Mata with the pistol.25

The district court’s determination that a defendant obstructed

justice within the meaning of U.S.S.G. § 3C1.1 is reviewed for

clear error. U

nited States v. Bethley

, 973 F.2d 396, 402 (5th Cir.

1992), cert. denied

, 113 S.Ct. 1323 (1993). In addition to hearing

the testimony of Mata at trial concerning the alleged threat, the

district court also heard the testimony of Garcia’s wife at the

sentencing hearing, who stated that she was with Garcia during the

alleged incident and that he never pointed the gun or made any

threats towards Mata. The court ruled against Garcia, stating that

it was making a credibility determination based on what it had

observed at trial and at the sentencing hearing. There is no basis

for finding that the district court’s credibility determination was

clearly erroneous. U nited States v. McAfee

, 8 F.3d 1010, 1018 (5th

Cir. 1993). Thus, the district court did not clearly err in making

the adjustment for obstruction of justice.

Finally, Garcia complains that the district court erred in

denying his objection to the four-level upward adjustment for his

role as an organizer in criminal activity involving five or more

participants. He contends that he did not exercise decision-making

authority such as setting the quantity and prices and that his only

participation, besides his telephone conversations with Mata, was

his introduction of Alcantar to Mata. He also argues that he did

not recruit the other codefendants and there was no evidence that

he was involved in the planning of the robbery.

This Court reviews a district court’s determination that a26

defendant held a supervisory role in an offense under U.S.S.G. §

3B1.1 for clear error. U nited States v. Musquiz

, 45 F.3d 927, 932-

33 (5th Cir.), cert. denied

, 116 S.Ct. 54 (1995). A defendant’s

offense level is increased by four levels if the defendant was an

organizer or leader of any criminal activity involving five or more

par ticipants or was otherwise extensive. U.S.S.G. § 3B1.1(a).

Proof that the defendant supervised only one oth er culpable

participant is sufficient to make the defendant eligible for this

enhancement. U

nited States v. Washington

, 44 F.3d 1271, 1281 (5th

Cir.), cert. denied

, 115 S.Ct. 2011 (1995). The evidence shows

that Garcia recruited Alcantar to carry o ut the scheme and

continued to oversee his activities. Alcantar recruited at least

six other men to participate in the robbery. The evidence was

s ufficient to support the district court’s imposition of the

adjustment.

Conclusion

Based on the foregoing, we A FFIRM Garcia’s conviction and

sentence.