                    UNITED STATES COURT OF APPEALS

                          FOR THE FIFTH CIRCUIT


                           __________________

                               No. 91-4502
                            Summary Calendar
                           __________________



     UNITED STATES OF AMERICA,

                                          Plaintiff-Appellee,

                                 versus

     RALPH HERNANDEZ,

                                          Defendant-Appellant.

            ______________________________________________

      Appeal from the United States District Court for the
                    Eastern District of Texas
         ______________________________________________

                             (June 3, 1992)


Before GARWOOD, HIGGINBOTHAM, and BARKSDALE, Circuit Judges.

GARWOOD, Circuit Judge:

     Defendant-appellant Ralph Hernandez (Hernandez) appeals his

conviction, following a jury trial, of one count of conspiracy to

distribute marihuana and four counts of possession of marihuana

with intent to distribute.      He challenges the sufficiency of the

evidence, complains of the denial of his request for a severance,

claims a fatal variance between the indictment and the evidence,

and contends that a witness was improperly allowed to assert her

privilege against self-incrimination.         He also challenges his

sentence.    We affirm.
                        Facts and Proceedings Below

       In    January   1989,   the   police   in   Plano,     Texas   began   an

investigation of a man named John Bass (Bass) on suspicion of drug

trafficking.           Their   investigation       entailed     almost   daily

surveillance during the early months of 1989.

       On the afternoon of April 4, 1989, Bass left his home and

drove a pickup truck to the parking lot of a local Bennigan's

restaurant.      A short time later a woman arrived in a rented Ryder

van.        Bass got into the passenger side of the van and conversed

with the driver, whom the police later determined to be Denise Pero

(Pero).      Soon thereafter a white Lincoln Continental pulled into

the parking lot, and Bass went over to talk with the driver, later

determined to be defendant-appellant Hernandez. Bass then got back

into his pickup truck and drove away.          Hernandez got into the van

with Pero, and they drove to a Holiday Inn in McKinney, Texas,

about fifteen miles north of Plano.

       About ten minutes later, Bass arrived driving the pickup

truck. Pero dropped Hernandez off at the Holiday Inn, and followed

Bass further northward on the highway. About five miles away, they

stopped at a service station, filled the vehicles with gas, and

switched vehicles:       Bass continued on in the Ryder van, and Pero

drove back toward McKinney in Bass's pickup truck.             Bass drove the

van to a ranch near Trenton, Texas belonging to his brother-in-law

Scott King (King), and pulled the van into King's garage.                 When

Bass left King's house and drove the van back onto the highway, the

police arrested him and took custody of the van.              They detected a

strong odor of raw marihuana in the van and found a partially

                                       2
smoked marihuana cigarette in the ash tray.             In the back of the van

were a suitcase and a cardboard box sealed with duct tape.                 After

obtaining a search warrant, they opened the box in the back of the

van and found a set of heavy-duty scales.             In the suitcase were a

number of smaller duffel-type bags.              The police obtained and

executed a search warrant on King's residence in the early morning

hours of April 5.        They found in the garage eight large boxes

containing marihuana--with a total net weight of slightly less than

300 pounds--and another large triple-beam scale.                 In the house

itself they found $8,050 in currency, several loaded handguns, and

several plastic bags containing marihuana. Pero and Hernandez were

arrested in the Bennigan's parking lot on the evening of April 4.

     Bass cooperated with the government and provided information

about his drug trafficking activities dating back to 1986.

     On   August   15,   1990,   Hernandez      and   eight    other   persons,

including Pero, were named in a 35-count indictment. Hernandez was

named in five counts:      (1) Count 1, charging all nine defendants

with conspiring, from October 1986 to the date of the indictment,

to distribute, and possess with intent to distribute, in excess of

1,000 kilograms of a substance containing a detectable amount of

marihuana,   in    violation     of       21   U.S.C.     §§   841(a)(1)     and

841(b)(1)(A)(vii); (2) Count 6, charging Hernandez and Pero with

possession with intent to distribute, and distribution of, between

180 and 200 pounds of marihuana on or about November 29, 1988; (3)

Count 11, charging Hernandez, Pero, and two others with possession

with intent to distribute, and distribution of, 200 pounds of

marihuana on or about January 29, 1989; (4) Count 14, charging

                                      3
Hernandez, Pero, and one other defendant with possession with

intent to distribute, and distribution of, 200 pounds of marihuana

on or about March 9, 1989; and (5) Count 16, charging Hernandez and

Pero with possession with intent to distribute, and distribution

of, approximately 315 pounds of marihuana on or about April 4,

1989.

     By the time of trial, Pero and several others named in the

indictment had entered into plea agreements, and Hernandez was

tried jointly with four codefendants.     The district court denied

his pretrial motion for a severance.        Bass's trial testimony

described the overall operations of the conspiracy.    He testified

that marihuana brought into the country in El Paso was brought by

courier to him in Plano (a small town near Dallas).    Bass utilized

a number of locations, including the rural homes of King and of one

Fred Harrington (Harrington), to inspect and weigh the marihuana,

and to store it until it could be sold to various persons who

distributed it in Ohio, Indiana, and Mississippi.     Bass testified

that in the spring of 1988 Pero called him and told him that she

could bring some marihuana to Dallas, if he was interested in

selling it.    Bass was receptive, because he was experiencing

difficulties with one of his regular suppliers, and he began to

purchase marihuana regularly from Pero.    He testified that on one

occasion in September or October of 1988 she was accompanied by

Hernandez, whom Pero said worked for the man who actually owned the

marihuana and was there to ensure that all of the money was paid

and returned safely to the owner.       Hernandez helped load the

marihuana into Bass's car on that occasion.     Bass testified that

                                4
thereafter during the fall of 1988, Hernandez accompanied Pero

several times on the drug transactions, that he participated in the

delivery of the marihuana, and that on at least one occasion Bass

paid Hernandez directly.

     Bass stated that on the day of his arrest, April 4, 1989, he

had met with Pero and Hernandez at the Bennigan's restaurant and

told them to go to the Holiday Inn in McKinney.         At the Holiday Inn

he suggested to Pero that in order to avoid attracting attention,

Hernandez   remain   there   while   the   two   of   them   drove   the   van

containing the marihuana to King's ranch.

     After the seventh day of the trial, at which point Bass was

testifying for the government during its case-in-chief, Hernandez's

four codefendants pleaded guilty.          At the beginning of the court

proceedings the next morning, the district court instructed the

jury as follows:

          "Ladies and gentlemen of the jury, you will notice
     that the Defendants, Fred Joseph Harrington, Brigitte
     Gaon Harrington, Stanley Diers and Morris Patterson are
     no longer present in Court.

          The reason these Defendants are not [sic] longer
     present here in Court is because of a ruling made by this
     Court. The reasons for the Court's ruling are not your
     concern. The absence of these Defendants should not be
     considered by you as affecting in any way your
     determination of the guilt or innocence of the Defendant,
     Ralph Hernandez who remains in Court."

A short time later, Hernandez unsuccessfully moved for a mistrial,

arguing   that   notwithstanding     the   court's    instruction,   it    was

perfectly clear to the jury that the other defendants had pleaded

guilty, and that it unfairly prejudiced his defense.

     Pero also testified for the government at the trial.                  She


                                     5
stated that an acquaintance of hers named Henry Barragan (Barragan)

had told her in early 1988 that he was going to have marihuana at

his disposal in Dallas, and that he was looking for someone to sell

it for him.   Pero, who had met Bass through her ex-husband's drug

activities, called Bass for this reason and arranged the initial

sale.   She testified that Barragan told her on this initial

occasion that he had 50 pounds of marihuana for her and 50 pounds

for someone else, whom she learned to be Hernandez when Barragan

introduced them in the spring of 1988.   She and Hernandez flew to

Dallas together and checked into a hotel. The marihuana was driven

to Dallas by Barragan's brother and delivered to them at the hotel.

Bass came to the hotel and purchased the 50 pounds from Pero.

Hernandez then asked Pero if she could also sell his 50 pounds to

Bass, so Pero called Bass again, and Bass returned to the hotel and

purchased the second 50 pounds from Pero.

     Pero testified that she and Hernandez continued to make

periodic trips to Dallas to sell marihuana to Bass throughout 1988

and spring of 1989, and that on those occasions Bass and Hernandez

met face-to-face, and Bass paid both of them for their marihuana.

On a few occasions, King came to meet them instead of Bass.    She

and Hernandez always flew to Dallas, and a third person would drive

the marihuana from El Paso to Dallas and deliver it to them.   Pero

testified that the driver was frequently Barragan's cousin Teresa

Chavez (Chavez).   On a few occasions, Pero and Hernandez went to

Dallas simply to pick up from Bass money Bass owed to Barragan from

a previous marihuana transaction.    Credit card slips produced by

the government earlier at trial established the dates of these

                                 6
trips by Pero and Hernandez as those charged in the indictment.

      Pero testified that on April 4, 1989, she and Hernandez had

come to Dallas to sell 300 pounds of marihuana belonging to

Hernandez.      She stated that at Hernandez's direction they went to

a convenience store, where they met two men who had driven the

Ryder van containing the marihuana from El Paso, and that Hernandez

instructed her to drive the van to the Bennigan's in Plano to meet

Bass.

      At the beginning of Hernandez's defense, his attorney informed

the court that he wished to call Chavez as a witness.                 Chavez had

pleaded guilty to one count of interstate travel in aid of a

racketeering        enterprise    (18   U.S.C.    §   1952)    charged   in   the

indictment, and was awaiting sentencing.                 Hernandez's attorney

later informed the court that after conferring with Chavez's

attorney, he believed that Chavez intended to invoke her Fifth

Amendment privilege against self-incrimination.                The court called

Chavez to the stand, and she informed the court that on advice of

counsel she would exercise her privilege against self-incrimination

if   summoned    to    testify.     Defense    counsel    then    proffered   the

questions he intended to ask Chavez and argued that given the

limited scope of his questioning, she could not have a valid Fifth

Amendment right to refuse to answer.             The district court disagreed

and excused Chavez.

      The jury convicted Hernandez on all counts.                The presentence

report (PSR) on Hernandez calculated a base offense level of 28 and

recommended     a     three-level   upward    adjustment      under   U.S.S.G.   §

3B1.1(b) for Hernandez's role as a supervisor in the charged

                                         7
offenses.    Hernandez objected to the three-level increase on the

basis that the trial evidence showed him merely to have been an

accomplice to Pero.        The district court overruled Hernandez's

objection, adopted the PSR's calculation of a total offense level

of 33,1 and sentenced Hernandez to concurrent terms of 135 months'

imprisonment and a five-year period of supervised release on each

count of conviction.      Hernandez brings this appeal.

                                Discussion

I.   Sufficiency of the Evidence

     Hernandez first challenges the sufficiency of the evidence.

Because he failed to move for a judgment of acquittal at any stage

of the trial, we review the sufficiency of the evidence only to

determine whether affirmance of his conviction would result in a

manifest    miscarriage   of   justice.      United   States   v.   Pruneda-

Gonzalez, 953 F.2d 190, 193 (5th Cir. 1992).

     For his conviction under Count 1 of the indictment, Hernandez

argues that other than the testimony of Bass and Pero, who were

testifying for the government in exchange for leniency, there was

nothing to show that he was involved in a conspiracy to distribute

marihuana; the police were only able to corroborate Bass and Pero's

account with credit card receipts showing that Hernandez had

travelled to Dallas, not with evidence independently showing that

he had engaged in illegal activity.

     There is no requirement that testimony by a co-conspirator



1
     The PSR also recommended, and the district court adopted, a
two-level increase for obstruction of justice that is not at
issue in this appeal.

                                    8
fulfilling a plea bargain be corroborated by independent evidence.

The jury is entrusted with the responsibility of evaluating the

witness's    credibility,      and   uncorroborated          testimony    of   a   co-

conspirator will sustain a guilty verdict unless, as is not the

case here, the testimony is incredible or otherwise insubstantial

on its face.    United States v. Osum, 943 F.2d 1394, 1405 (5th Cir.

1991); United States v. Gardea Carrasco, 830 F.2d 41, 44 (5th Cir.

1987).

      In the present case, the existence of plea agreements by Bass

and Pero was fully disclosed to the jury during direct examination

of those witnesses, and the jury was instructed that testimony from

an alleged accomplice who has entered into a plea agreement "is

always to be received with caution and weighed with great care,"

and   that    "[y]ou   should    never       convict    a    Defendant     upon    the

unsupported testimony of an alleged accomplice unless you believe

that testimony beyond a reasonable doubt."                   The jury nonetheless

credited Bass and Pero's version of events, a decision we will not

disturb,     because   their    testimony      was     far   from   incredible     or

insubstantial.     Bass and Pero's testimony was more than sufficient

to establish the requisite elements for a conspiracy conviction

under 21 U.S.C. § 846, i.e., (1) the existence of an agreement

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

Hernandez knew of the agreement and intended to join it, and (3)

that Hernandez did participate in the conspiracy.                        See, e.g.,

United States v. Juarez-Fierro, 935 F.2d 672, 677 (5th Cir.), cert.

denied, 112 S.Ct. 402 (1991).

      Hernandez   challenges      his    convictions         for   the   substantive

                                         9
counts of possession with intent to distribute primarily on the

same basis--that they rest on the uncorroborated testimony of Bass

and Pero.      For the reasons set forth above, this argument is

unavailing.    Hernandez also notes that neither Bass nor Pero was

specific as to the dates when the supposed transactions took place.

Although he is correct that in many cases Bass or Pero could recall

only a general time frame for the transactions, the jury was aided

by the credit card records and hotel receipts showing exactly when

Pero and Hernandez had travelled to Dallas.           Moreover, when the

indictment uses the "on or about" terminology employed in this

case, the prosecution is not obligated to prove the precise date of

the offense.      See United States v. Tunnell, 667 F.2d 1182, 1186

(5th Cir. 1982).

      Hernandez    has   demonstrated    no   possibility   of   a   manifest

miscarriage of justice in affirmance of his convictions based on

the evidence produced at trial.         Indeed, the evidence was clearly

more than sufficient to sustain the convictions under any standard.

II.   Denial of Severance

      Hernandez next argues that the joinder of his case with those

of the codefendants was prejudicial, and that the district court

therefore erred in denying his motion for severance, made pursuant

to Federal Rule of Criminal Procedure 14.             The basis for his

argument is that his codefendants were people such as Harrington

who cooperated with Bass in storing the drugs in the Dallas area

and preparing them for distribution and resale, and that Hernandez

never had any occasion to deal directly with them or conspire with

them for any common purpose.

                                    10
     The decision of whether to sever the trials of persons who are

indicted together is within the discretion of the trial court, and

the denial of a severance will not furnish grounds for reversal

unless the defendant can demonstrate specific compelling prejudice

against which the district court was unable to afford protection.

United States v. Capote-Capote, 946 F.2d 1100, 1104 (5th Cir.

1991), petition for cert. filed (1-23-92); United States v. Massey,

827 F.2d 995, 1004 (5th Cir. 1987).   Any possible prejudice must,

moreover, be balanced against the public's interest in efficient

judicial administration.   United States v. Lindell, 881 F.2d 1313,

1319 (5th Cir. 1989), cert. denied, 110 S.Ct. 2621 (1990); United

States v. Fortna, 796 F.2d 724, 737 (5th Cir.), cert. denied, 107

S.Ct. 437 (1986).

     Hernandez's general assertions of prejudice arising from the

joinder with other co-conspirators fall well short of the required

showing of specific and compelling prejudice.      Although we have

recognized the possibility of prejudice from a "spillover effect"

if there is "a quantitative and qualitative disparity in the

evidence among the co-defendants," United States v. Rocha, 916 F.2d

219, 228 (5th Cir. 1990), cert. denied, 111 S.Ct. 2057 (1991),

Hernandez has not demonstrated such a disparity.    Indeed, he does

not base his argument on any specific evidence admitted at trial

that would have been inadmissible against him alone.        Limited

involvement in a conspiracy does not by itself entitle a defendant

to severance.   Id.; Fortna, 796 F.2d at 738.   Although he claims

that he was prejudiced by the mid-trial withdrawal of the other

defendants, he again fails to specify how that prejudice arose, and

                                11
we find no support for that view in the record.   The district court

gave an explanation for the departure of the other defendants that

was calculated to prevent prejudice to Hernandez, and the jury was

also instructed before retiring that "[t]he Defendant is not on

trial for any act, conduct or offense or offenses not alleged in

the indictment," and that the jury should not be "concerned with

the guilt or [sic] any other person or persons not on trial as a

Defendant in this case."    The court further instructed the jury

that once a defendant was determined to have been part of a

conspiracy, acts done in knowing furtherance of the conspiracy were

evidence against him even if he had not been aware of them, but

that the jury had to make the initial determination of membership

in the conspiracy based solely on the particular evidence against

the defendant:

     "In determining whether a Defendant was a member of an
     alleged conspiracy, however, you should consider only the
     evidence, if any, pertaining to his own acts and
     statements.   He is not responsible for the acts or
     declarations of other alleged participants until it is
     established beyond a reasonable doubt first that a
     conspiracy existed, and second, that the Defendant was
     one of the members."

Hernandez has failed to demonstrate how these precautions by the

district court were ineffective to protect him against prejudice,

and accordingly he has demonstrated no abuse of discretion in the

district court's refusal to sever the cases initially or grant a

mistrial after the guilty pleas of his codefendants.

III. Material Variance

     At trial Hernandez requested an instruction clarifying the

government's burden to prove the single conspiracy alleged in the


                                12
indictment.    His requested instruction read in part as follows:

          "In order to sustain its burden of proof for this
     charge, the government must show that the single
     conspiracy alleged in Count 1 of the indictment existed.
     Proof of separate or independent conspiracies is not
     sufficient.

            . . . .

          Even if the evidence in the case shows that
     Defendant was a member of some conspiracy, but that this
     conspiracy is not the single conspiracy charged in the
     indictment, you must acquit Defendant.

          Unless the government proves the existence of the
     single conspiracy described in the indictment beyond a
     reasonable doubt, you must acquit Defendant."

The district court declined the requested instruction and overruled

Hernandez's objection to its omission.          The instructions given to

the jury did not address the question of multiple conspiracies.

Hernandez    contends   on   appeal   that   the   instructions    permitted

conviction    despite   a    material      variance   between   the   single

conspiracy alleged in the indictment and the multiple conspiracies

he claims were shown by the evidence at trial.

     We have held that a variance between the offense charged in

the indictment and the proof relied upon at trial constitutes

reversible error if it affects the substantial rights of the

defendant.    United States v. Lokey, 945 F.2d 825, 832 & n.1 (5th

Cir. 1991); United States v. Guerra-Marez, 928 F.2d 665, 671 (5th

Cir.), cert. denied, 112 S.Ct. 322 (1991). The concerns underlying

our cases on variance are to ensure that the indictment notifies a

defendant adequately to permit him to prepare his defense, and does

not leave the defendant vulnerable to a later prosecution because

of failure to define the offense with particularity.              Lokey, 945


                                      13
F.2d at 832-33; United States v. Richerson, 833 F.2d 1147, 1155

(5th Cir. 1987). In cases dealing with an alleged variance between

a   single-conspiracy     indictment     and   evidence   showing   multiple

conspiracies, this concern focuses on the danger of transference of

guilt, i.e., the danger that despite demonstrating his lack of

involvement in the conspiracy described in the indictment, a

defendant may be convicted because of his association with, or

conspiracy for other unrelated purposes with, codefendants who were

members of the charged conspiracy.          See Guerra-Marez, 928 F.2d at

672;   Richerson,   833   F.2d   at    1155.     Accordingly,   a   multiple

conspiracy instruction forcefully reminds the jury that it must

acquit the defendant if it concludes that he was not a member of a

conspiracy charged against him, even if it finds that he was a

member of an uncharged conspiracy.          See Guerra-Marez, 928 F.2d at

672 n.7; United States v. Toro, 840 F.2d 1221, 1236 (5th Cir.

1988).

       In the present case, several factors minimize the concern that

transferred guilt contributed to the jury's guilty verdict for

Hernandez. First, Hernandez's defense at trial was not directed to

establishing the separateness of his dealings with Bass from any of

Bass's other operations; the defense that Hernandez presented for

the jury to accept or reject was that he had never had any knowing

involvement in any marihuana or other drug trafficking and was not

a part of any conspiracy.             Second, because all of the other

defendants had dropped out of the case before the government's

case-in-chief was completed, there is strong reason to presume that

the jury's attention was properly focused only on Hernandez's

                                       14
conduct when the case was submitted to it.

       Hernandez argues on appeal that the government proved only a

series of component conspiracies between Bass and his various

suppliers and distributors, but that no reasonable jury could have

inferred a single agreement among the various codefendants.                  We

disagree.       Whether the evidence shows one or multiple conspiracies

is a factual determination principally based on three factors: (1)

the existence of a common goal or purpose, (2) the nature of the

scheme,    and    (3)   overlapping     of   participants    in   the    various

dealings.       Guerra-Marez, 928 F.2d at 671; Richerson, 833 F.2d at

1153.    Hernandez's protestation that he had no dealings with some

of his codefendants, even if correct, is not dispositive:                    the

overlapping of participants contemplated by the factors above may

be fulfilled if a pivotal figure such as Bass directs and organizes

the illegal activity and has extensive dealings with each of the

parties.    See Lokey, 945 F.2d at 833; United States v. DeVarona,

872 F.2d 114, 119 (5th Cir. 1989); Richerson, 833 F.2d at 1154.

       Moreover, the consideration that this Court found decisive in

Lokey, DeVarona, and Richerson--whether the activities of one

aspect of the scheme were necessary to or advantageous to the

success of other aspects or of the overall venture--is present in

this    case.      As   must   have   been   obvious   to   Hernandez,    Bass's

willingness and ability to pay him cash for large quantities of

marihuana in their frequent sales depended upon Bass's continued

ability to steadily move the marihuana further along in the chain




                                        15
toward the eventual consumer.2

     That   the   evidence   supported   the   existence   of   a   single

conspiracy, however, does not necessarily preclude the possibility

that a jury could rationally have found multiple conspiracies to be

present, and thus does not necessarily resolve the issue of the

district court's refusal to give the requested jury instruction; a

defendant is generally entitled to an instruction on any defensive

theory for which the evidence is sufficient for a reasonable jury

to rule in favor of the defendant on that theory.     United States v.

Stowell, 953 F.2d 188, 189 (5th Cir. 1991) (per curiam), cert.

denied, 112 S.Ct. 1269 (1992); see also United States v. Erwin, 793

F.2d 656, 663 (5th Cir.), cert. denied, 107 S.Ct. 589 (1986).

However, we are not convinced that the refusal here warrants

reversal.   For a refusal to give a requested jury instruction to

constitute reversible error, the instruction (1) must have been

substantially correct, (2) must not have been substantially covered

in the charge given to the jury, and (3) must have concerned an



2
     In this context, the claim that any possible variance from a
single-conspiracy indictment prejudiced Hernandez's substantial
rights is very weak. We have already noted that there was no
meaningful "transference of guilt" risk. Further, even assuming
arguendo that the trial evidence would have supported the
conclusion that the transportation of the marihuana to Plano and
its sale to Bass was accomplished pursuant to a separate
conspiracy from the one by which Bass stored the marihuana in the
Dallas area and transferred it for distribution in other regions
of the country, the two (or multiple) conspiracies had the same
criminal objective, and their members would have been subject to
prosecution for the same offense. In other words, this is not a
case where Hernandez's possible inclusion in a larger conspiracy
exposed him, through the vicarious liability doctrine of
Pinkerton v. United States, 66 S.Ct. 1180 (1946), to prosecution
for an offense more severe than that chargeable against him as a
member solely of the smaller conspiracy.

                                  16
important issue so that the failure to give it seriously impaired

the defendant's ability to present a given defense.              United States

v. Allison, 953 F.2d 870, 876 (5th Cir. 1992); United States v.

Terrazas-Carrasco, 861 F.2d 93, 95 (5th Cir. 1988).                  As noted

above, the absence of an instruction on multiple conspiracies did

not seriously impair Hernandez's ability to present, as he did

through his own testimony, his already chosen defense of total lack

of involvement in any conspiracy or criminal conduct whatever.

Further, under the evidence and with the case in the posture that

it was when it went to the jury, it is simply inconceivable that

the jury would have failed to convict Hernandez for his conspiracy

with Bass and Pero but would have nevertheless at the same time

found him guilty of being a member of some separate conspiracy

between Bass and out of state distributors no part of which

included Hernandez's marihuana dealings with Bass and Pero. So far

as the evidence showed, Hernandez was either guilty of nothing or

guilty of being a member of a marihuana distribution conspiracy

that included himself, Bass, Pero and others.             No uncharged third

alternative was suggested by the evidence.          Moreover, it is highly

questionable     whether   Hernandez's         proposed    instruction    was

substantially correct.          The instruction quoted above did not

adequately     explain   that    proof    of    separate    or    independent

conspiracies did not mandate acquittal so long as one of those

conspiracies fit the description contained in the indictment, and

Hernandez's participation in that conspiracy was established by the

evidence.    See Guerra-Marez, 928 F.2d at 671-72.

     We conclude that because the evidence so strongly supported a

                                     17
finding of a single conspiracy, and because under these facts any

arguable variance from the indictment could not have prejudiced

Hernandez's substantial rights, Hernandez's claim of a material

variance is unavailing.      We further conclude that because his

requested jury instruction was not substantially correct, and

because its absence did not seriously impair the defense presented

at trial, it was not reversible error for the district court to

refuse to give Hernandez's instruction.3

IV.   Chavez's Invocation of the Fifth Amendment

      Hernandez's fourth claim of error is that the district court

erroneously   permitted   Chavez   to   invoke   the   Fifth   Amendment,

because, having entered a guilty plea, Chavez no longer enjoyed a

privilege against self-incrimination.

      It is well settled that a defendant's Sixth Amendment right of

compulsory process to obtain witnesses in his favor must yield to

a witness's Fifth Amendment privilege against self-incrimination.

See, e.g., Roussell v. Jeane, 842 F.2d 1512, 1516 (5th Cir. 1988);

United States v. Khan, 728 F.2d 676, 678 (5th Cir. 1984).             The

trial judge, moreover, "necessarily is accorded broad discretion in

determining the merits of a claimed [Fifth Amendment] privilege."

United States v. Lyons, 703 F.2d 815, 818 (5th Cir. 1983).



3
     It is also doubtful that Hernandez has adequately presented
on appeal any complaint of the denial of his requested
instruction. No claimed instructional error is listed in the
statement of the issues in his brief, nor is any mentioned in his
summary of the argument or in any of the argument headings in his
brief. The matter is mentioned only in the argument section of
the brief dealing with the contention that "there was a variance
between the conspiracy charged in the indictment and the
conspiracy proved at trial."

                                   18
     Hernandez relies on the principle that once a defendant has

been convicted of, or has pleaded guilty to, an offense, the

privilege ceases to apply as to that offense and as to any other

charges in an indictment that the government promises to dismiss as

part of the plea agreement.    See, e.g., United States v. Pardo, 636

F.2d 535, 543 (D.C. Cir. 1980).         However, Chavez had not been

sentenced at the time of Hernandez's trial.         As other courts of

appeals have held, impending sentencing may furnish grounds for a

legitimate fear of incurring additional criminal liability from

testifying, in which case the privilege should remain in effect.

See United States v. Lugg, 892 F.2d 101, 102 (D.C. Cir. 1989);

United States v. Tindle, 808 F.2d 319, 325 (4th Cir. 1986); Bank

One of Cleveland, N.A. v. Abbe, 916 F.2d 1067, 1075-76 (6th Cir.

1990); United States v. Trejo-Zambrano, 582 F.2d 460, 464 (9th

Cir.), cert. denied sub nom. Fierro-Soza v. United States, 99 S.Ct.

618 (1978).    From the record before us, we cannot preclude that

reasonable    possibility,   and   we   therefore   find   no   abuse    of

discretion in the district court's deferral to Chavez's invocation

of the Fifth Amendment.

V.   Increase in Offense Level

     Hernandez's final contention is that the district court erred

in increasing his offense level by three levels based on the PSR's

finding that he was a supervisor within the meaning of U.S.S.G. §

3B1.1(b).    Hernandez has not provided this Court with a transcript

of the sentencing hearing, or offered any justification for not

doing so.     We therefore consider this contention waived.             See

United States v. Hinojosa, No. 91-2260, slip op. at 3933-34 (5th

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Cir. Apr. 3, 1992).

                           Conclusion

     Because we find all of Hernandez's contentions unavailing to

establish reversible error, the judgment and sentence of the

district court are

                                                        AFFIRMED.




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