United States Court of Appeals
                            FOR THE EIGHTH CIRCUIT
                                  ___________

                                  No. 03-1886
                                  ___________

United States of America,              *
                                       *
                     Appellee,         *
                                       * Appeal from the United States
      v.                               * District Court for the
                                       * Southern District of Iowa.
Robert Frederick Johnston, Jr.,        *
                                       C      [PUBLISHED]
                                       *
                    Appellant.         *
                                  ___________

                             Submitted: October 22, 2003

                                  Filed: December 24, 2003
                                   ___________

Before LOKEN, Chief Judge, and HEANEY and MORRIS SHEPPARD ARNOLD,
      Circuit Judges.
                               ___________

PER CURIAM.


       Robert Frederick Johnston, Jr., was convicted of one count of conspiracy to
distribute methamphetamine, in violation of 21 U.S.C. §§ 841(a)(1), 841(b)(1)(A),
and § 846. Johnston contends the district court1 committed reversible errors during


      1
       The Honorable Robert W. Pratt, United States District Court for the Southern
District of Iowa.
trial and improperly applied the United States Sentencing Guidelines in sentencing
him to 210 months in prison. First, Johnston argues that the district court should have
granted a mistrial after the government introduced evidence of his involvement with
methamphetamine outside of the dates in the indictment. Second, Johnston claims
that the district court should not have admitted evidence of controlled buys that did
not involve him. Finally, Johnston maintains the district court’s sentencing was
flawed for three reasons: 1) the district court erroneously determined the drug
quantity attributable to him; 2) the district court should have granted a downward
adjustment for his mitigating role; and 3) the district court should have granted a
downward adjustment for his acceptance of responsibility. Finding no reversible trial
or sentencing errors, we affirm the district court.

                                    Background

       In addition to Johnston, the drug conspiracy involved Lori Arnold, Robert
Paris, Charles William Chilton, Marco Armenta, William Wilt. Johnston was
independently charged for his role in the conspiracy. Arnold, Armenta, and Wilt all
pled guilty to charges stemming from their participation in the conspiracy, and were
sentenced to 131 months, 84 months, and 72 months respectively. The conspiracy
operated in the following manner: Arnold, Paris, and Chilton bought large quantities
of methamphetamine from Armenta, who obtained the methamphetamine from
suppliers elsewhere. Arnold shared some of the methamphetamine with her then-
boyfriend,2 Wilt, and sold the rest.           Johnston sold small quantities of
methamphetamine that he obtained from Arnold or Paris to Charles Arden Jackson,
a user, and Armenta, and also acted as Paris and Arnold’s courier, shuttling drugs and
money for larger deals.




      2
          Arnold and Wilt are now married.

                                         -2-
        Jackson, Arnold, Armenta, and Wilt, all testified against Johnston at trial.
Armenta testified that he bought a total of an eighth of an ounce of methamphetamine
from Johnston, and that Johnston was present during a negotiation between Chilton
and Armenta’s suppliers. Arnold testified that she sold Johnston two ounces of
methamphetamine, and sold one ounce to Jackson on Johnston’s behalf. Wilt
testified that he sold Johnston a total of one-quarter ounce, that he witnessed Johnston
buy small quantities3 from Arnold and Paris, and that he gave Johnston two ounces
that Johnston then delivered to Paris as satisfaction for a debt Wilt owed to Paris.
Jackson testified he bought a half ounce of methamphetamine from Johnston during
the summer of 2001.

       Johnston played a role in two drug deals involving larger quantities of drugs.
One drug deal occurred in June 2001, and the other in July 2001. Arnold testified
that in June, she used Johnston to deliver $4,200 to Chilton. Paris, Chilton, and
Arnold were pooling their money to buy five pounds of methamphetamine from
Armenta’s suppliers. The deal went awry, and Arnold gave Johnston an additional
$4,200 to deliver to Chilton in order to appease the suppliers.4 In late July of 2001,
Wilt and Arnold both testified that Johnston again acted as a money courier. Paris
was out of town for this deal, and left Johnston in charge of delivering money to
Chilton. Arnold testified that Johnston handled $20,0005 for this deal; Wilt recalls
counting out $15,000 of Arnold’s money for this deal, but was only aware of
Johnston’s involvement through phone calls he overheard between Paris and


      3
       While not exact, Wilt estimated these smaller quantities ranged from one-
sixteenth of an ounce to a quarter ounce.
      4
       Armenta’s recollection of this event differed from Arnold’s recollection.
Armenta remembered picking up an additional $2,500 from Johnston in order to
pacify the suppliers, and maintains the transaction was for two pounds of
methamphetamine, not five pounds as Arnold testified.
      5
          Arnold contributed $15,000, with Chilton contributing $5,000.

                                          -3-
Johnston. The July deal was supposed to be for ten pounds of methamphetamine, but
according to Arnold, only five pounds changed hands. Johnston delivered to Arnold
her two-and-a-half pound portion.

       The police learned of the drug conspiracy when Jackson began cooperating
with the police after he violated the terms of his probation. Jason Fuller, at the time
a Special Agent with the Iowa police department, staged several buys from Arnold
with Jackson’s cooperation. Agent Fuller testified that Johnston was present for one
of these buys involving 111.79 grams of methamphetamine,6 although there is no
indication that he actively participated in the sale.7 Johnston was never found with
marked money from any of the controlled buys.

       On May 10, 2002, Johnston was arrested. At that time, he admitted he was a
methamphetamine user, had received methamphetamine from Arnold, and had sold
a portion of his one-eighth ounce quantities to support his habit. Johnston told police
that he was around Paris and large quantities of drugs, and he identified Paris’s
buyers. He also admitted that when Paris was out of town, he had $20,000 that he
was supposed to deliver for a drug buy; he claimed he did not deliver the money
though, and that Arnold picked it up. Johnston remembered being present for a deal
with the undercover agent as well.

        Johnston was indicted for conspiring to distribute 500 grams or more of
methamphetamine. The jury found him guilty of conspiring to distribute less than
fifty grams of methamphetamine. At sentencing, the district court attributed 2,560.51


      6
      Only half of the methamphetamine in this sale was purity tested: 55.84 grams
were 27% pure, while the remaining 55.95 grams were not purity tested.
      7
      In fact, during Arnold’s cross examination, she admitted Johnston entered the
room during this controlled buy, probably to ask her a question about electrical work
he was completing in her bar.

                                         -4-
grams of methamphetamine to Johnston and determined his base level offense was
34, with a criminal history category of IV. The district court sentenced him to 210
months in prison.

                                     Discussion

I. Mistrial

       Johnston first argues that the district court erred by not declaring a mistrial
after Jackson’s testimony. We review a district court’s refusal to grant a mistrial
using an abuse of discretion standard. United States v. Washington, 

,
859 (8th Cir. 2003).

      Jackson testified during the prosecution’s direct examination as follows:

      Q: How long have you known Reid Paris?
      A: Since about 2001.
      Q: How long have you known Howdy?8
      A: Since about ’95.
      Q: Have you ever known Howdy to be involved in methamphetamine?
      A: Yes.
      Q: And when did you first become aware of that?
      A: Probably ’95.
      Q: Did there come a time that you obtained methamphetamine from
      Howdy?
      A: Yes.
      Q: When did you obtain methamphetamine from Howdy?
      A: In 2001.


      8
          Johnston is also known as “Howdy.”

                                         -5-
      Q: About when did that occur first?
      A: Probably the summer.

(Partial Trial Tr. Test. of Charles Jackson at 8.)

      The indictment alleged Johnston was involved in a methamphetamine
conspiracy from April 1, 2001, through October 26, 2001. Johnston maintains that
Jackson’s reference to his involvement with methamphetamine since 1995 was
grounds for a mistrial for three reasons: 1) Jackson’s testimony should have been
barred by Federal Rule of Evidence 404(b) as propensity evidence; 2) Jackson’s
testimony served as an impermissible amendment or as a material variance to the
indictment; and 3) it was prosecutorial misconduct for the prosecution to inquire
about his 1995 involvement with methamphetamine.

      A. Propensity Evidence

      In response to Jackson’s testimony, the district court delivered the following
cautionary instruction to the jury:

      Evidence has been introduced by a Government witness that purports to
      suggest that Mr. Johnston was involved in drug activity not covered
      during the period of this indictment. The evidence should not have been
      injected into this trial. You are to disregard the testimony. You cannot
      use that testimony in your deliberations in any manner. The Court, by
      this ruling, strikes the testimony and prohibits the prosecution from any
      further reference to that testimony in this proceeding.

(Trial Tr. Vol. III at 368.)

       The court, unless there is evidence to the contrary, should assume that a jury
will follow a curative instruction. United States v. Uphoff, 

, 626 (8th


                                          -6-
Cir. 2000). The jury was instructed not to consider Jackson’s reference to Johnston’s
 1995 involvement with methamphetamine. In fact, the district court’s instruction
struck the portion of Jackson’s testimony that Johnston maintains was prohibited by
Federal Rule of Evidence 404(b). We are satisfied that this admonishment adequately
protected Johnston from having Jackson’s testimony improperly used against him.

      B. Constructive Amendment or Material Variance to the Indictment

       Johnston next argues that Jackson’s testimony served as a constructive
amendment or as a variance to the indictment by introducing evidence outside of the
dates of the indictment. A constructive amendment, which is reversible error per se,
occurs when the essential elements of the indicted offense are altered, either actually
or in effect, after the grand jury has issued the indictment. United States v. Novak,

, 574 (8th Cir. 2000). In order to determine whether the indictment was
constructively amended, the court must consider “whether the admission of certain
evidence created a ‘substantial likelihood’ that [the defendant] was convicted of an
uncharged offense.” 

The Eighth Circuit has described a variance, on the
other hand, as “chang[ing] the evidence, while the charge remains the same.” United
States v. Stuckey, 

, 981 (8th Cir. 2000). A variance is grounds for a
reversal only if the defendant has been prejudiced by the change in evidence. 

.

       As stated above, the jury was instructed to ignore Jackson’s testimony as it
related to periods of time outside of the indictment. Our review of the record reveals
that the prosecution did not explore the 1995 time frame with Jackson. The focus of
the prosecution’s direct and redirect examination was on Jackson’s knowledge of
Johnston’s conduct as it related to the conspiracy in 2001. Because of this, Jackson’s
reference to 1995 did not create a substantial likelihood that Johnston was convicted




                                         -7-
of drug trafficking in 1995.9 We therefore find that Jackson’s testimony did not
amend the indictment, or function as a variance to the indictment.

      C. Prosecutorial Misconduct

       Johnston maintains that the prosecutor acted improperly by asking Jackson
when he first knew of Johnston’s involvement with methamphetamine. To find
prosecutorial misconduct, the court must examine whether the prosecutor made
improper remarks and whether those remarks “prejudicially affected the defendant[’s]
substantial rights so as to deprive [him] of a fair trial.” United States v. Wadlington,

, 1077 (8th Cir. 2000). Three factors are used to assess the prejudicial
impact on a defendant: “1) the cumulative effect of the misconduct; 2) the strength
of the properly admitted evidence; and 3) the curative actions taken by the district
court.” 

no indication that the prosecutor was aware of Johnston’s involvement
with methamphetamine in 1995 prior to examining Jackson. The government asked
an open-ended question; the question itself was not improper. Again, the district
court’s curative instruction corrected any prejudice Jackson’s comment may have
caused Johnston. We do not find that the prosecutor’s actions rose to the level of
misconduct required to declare a mistrial.

II.   Admissibility of Evidence of Controlled Buys that Did Not Involve the
      Defendant

      Johnston argues that the district court abused its discretion by admitting
evidence of controlled buys that did not involve him. We review a district court’s


      9
        Further, since the facts around the 1995 comment were not developed, the
jury could not have used this evidence in reaching its decision about the conspiracy
in 2001.

                                          -8-
decision to admit such evidence using an abuse of discretion standard; if the district
court’s error in admitting the evidence was harmless, we will not reverse the district
court. United States v. Oleson, 

, 1091 (8th Cir. 2002).

       In a conspiracy case, “each member of a conspiracy may be held criminally
liable for any substantive crime committed by a co-conspirator in the course and
furtherance of the conspiracy, even though those members did not participate in or
agree to the specific criminal act.” United States v. Escobar, 

, 1420 (8th
Cir. 1995) (quoting United States v. Lucas, 

, 1220 (8th Cir. 1991)). We
agree with the district court that the controlled drug buys were relevant in this case
because they illustrated the extent of the conspiracy’s operation. Even though
Johnston may not have been directly involved in the buys (although he was at least
present during one such buy), he can still be held responsible for the reasonably
foreseeable buys that occurred on behalf of the conspiracy. 

complained-of evidence involved sales by co-conspirators to an undercover agent.
The district court, therefore, did not abuse its discretion by admitting testimony
relating to these buys.

III. The Drug Quantity Used at Sentencing

       The district court sentenced Johnston for conspiring to distribute 2,560.51
grams of methamphetamine, even though the jury found him guilty of conspiring to
distribute less than fifty grams of methamphetamine. Johnston maintains that the
evidence does not support the district court’s drug quantity determination.

      We review the district court’s application of the Sentencing Guidelines de
novo. United States v. Barrios-Perez, 

, 780 (8th Cir. 2003). The district
court’s factual findings in relation to drug quantity are reviewed for clear error. 

Court must determine the amount of drugs for which a criminal



                                         -9-
defendant is responsible by a preponderance of the evidence.” United States v.
Gallardo-Marquez, 

, 1124 (8th Cir. 2001).

       Johnston states he only played a minor part in the conspiracy, if he played any
part at all, and that the government did not prove by a preponderance of the evidence
that he could have reasonably foreseen the full extent of the conspiracy. Johnston
also directs us to the jury verdict finding him responsible for conspiring to distribute
fifty grams or less of methamphetamine, although he concedes that for sentencing
purposes the evidence supports his involvement with 139 grams of
methamphetamine; this would bring his base level offense down to 26. The
government responds that 1) the jury verdict could have been influenced by factors
independent of Johnston’s actual involvement in the conspiracy, and 2) the district
court based its quantity determination on sufficiently reliable evidence.

       The district court can impose a sentence based on a higher drug quantity
determination than the jury’s finding so long as the sentence does not exceed the
statutory maximum of the convicted offense. See United States v. Titlbach, 

, 921-22 (8th Cir. 2002) (affirming the district court’s drug quantity determination
of 172.03 grams of methamphetamine, even though the jury found the defendant
guilty of a conspiracy involving fifty grams or less); United States v. Caldwell, 

, 533 (8th Cir. 2001) (per curiam) (“The use of a judicially determined drug
quantity as a basis for sentencing is permissible . . . so long as the defendant’s
sentence does not exceed the statutory maximum sentence available for an
indeterminate amount of the drug.” (citing United States v. Aguayo-Delgado, 

, 933-34 (8th Cir. 2000), cert. denied, 

)). Here, the district
court’s sentencing of Johnston does not run afoul of this rule.10


      10
      The statutory maximum for conspiracy to distribute fifty grams of
methamphetamine is twenty years, 21 U.S.C. § 841(b)(1)(C), longer than Johnston’s
210 month sentence.

                                         -10-
       In reaching its quantity determination, the district court had to make credibility
determinations. Our review of the record reveals weaknesses in some of the
witnesses’ testimony and some conflicting testimony.11 The district court, however,
has considerable discretion in determining the credibility of witnesses, and we do not
find the district court abused its discretion in assessing the trial testimony. See
United States v. Carter, 

, 461 (8th Cir. 1993).

        Arnold, Armenta, Wilt, and Jackson all testified as to Johnston’s involvement
with the conspiracy. Armenta and Arnold both testified that Johnston handled money
for a June deal involving two pounds of methamphetamine.12 Arnold and Wilt
testified that in July, Johnston acted as a courier to complete a drug deal for five
pounds of methamphetamine while Paris was out of town. We find that the testimony
describing Johnston’s involvement with the deals in June and July of 2001, connects
him to 2,268 grams of methamphetamine by a preponderance of the evidence. This
amount alone is sufficient to justify Johnston’s base offense level of 34.
Additionally, Arnold admits to selling Johnston an ounce on two occasions, and
selling another ounce to Jackson on Johnston’s behalf (85.05 grams); Armenta and
Jackson testified to buying methamphetamine from Johnston in an amount totaling
17.72 grams; Wilt admits to selling Johnston 7.08 grams and fronting Johnston 56.7
grams on Paris’s behalf; and Agent Fuller places Johnston at a controlled buy
involving 111.79 grams of methamphetamine. Accordingly, our review of the


      11
        For instance, Arnold, during her cross examination admitted she had lied
during her direct examination in regards to Wilt’s involvement with the conspiracy.
Certainly this admission could be used to discredit the entirety of Arnold’s testimony.
Additionally, while Arnold and Armenta both testified as to Johnston’s participation
in the June 2001 deal, each testified to a different amount of methamphetamine
involved in the deal.
      12
       Armenta testified that the June 2001 deal involved two pounds, or 907.20
grams, of methamphetamine, while Arnold testified the deal involved five pounds.
We are using the lower amount to calculate the drug quantity.

                                          -11-
evidence indicates a preponderance of the evidence connects Johnston to 2,546.34
grams of methamphetamine. While this amount is slightly lower than the district
court’s determination, either amount results in the same base offense level.
Therefore, we find the district court was within its discretion to sentence Johnston
using a base offense level of 34.

IV. Mitigating Role Adjustment

       Johnston maintains the district court should have granted him a mitigating role
adjustment, of either two or three levels, pursuant to United States Sentencing
Guideline § 3B1.2. The district court’s decision regarding a role reduction is a fact
determination, which we review for clear error. United States v. Thurmon, 

, 792 (8th Cir. 2002). “A defendant’s role in the offense is measured by the
relevant conduct for which he is held responsible.” 

district court has
determined the relevant conduct, each participant’s actions should be compared
against the other participants, and each participant’s culpability should be evaluated
in relation to the elements of the offense. 

that he did not negotiate any deals or put any of his own
money into the conspiracy for the purpose of buying mass quantities of drugs. He
claims he was just a user and a gopher who did not even have a cellular telephone.
Johnston was never found with any marked money, and was not an active participant
in any of the controlled buys. In response, the government stresses Johnston’s role
as manager of the drug operation when Paris was absent.

        The district court, by using the 2,560.51 grams of methamphetamine as the
basis for sentencing Johnston , defined the relevant conduct as the wider conspiracy.
The district court stated that “the defendant knew a great deal about the drug
operation . . . and that he helped collect money and make distributions.” (Sentencing
Tr. at 15.) Arnold, a person who knew more about the conspiracy than Johnston , was

                                        -12-
only sentenced to 84 months, while Johnston was sentenced to 210 months. This is
troubling. Ultimately, however, we do not think the district court’s conclusion about
Johnston’s role in the conspiracy was clearly erroneous. Johnston acted as the go-
between on several different drug buys, either delivering the drugs, or delivering the
money. When Paris was out of town, he used Johnston as a courier to complete a
sale. This supports the district court’s observation that Johnston knew, and
participated in, the full extent of the conspiracy. Accordingly, the district court did
not abuse its discretion in refusing to grant Johnston a downward departure for a
minor participant role, particularly in light of his criminal history.

V. Acceptance of Responsibility Adjustment

      Johnston finally argues the district court should reduced his sentence because
he accepted responsibility for his actions. A court may reduce a defendant’s offense
level by two levels where the defendant clearly demonstrates acceptance of
responsibility. USSG § 3E1.1. The comment makes clear, however, that this
reduction does not often apply to defendants who go to trial:

      This adjustment is not intended to apply to a defendant who puts the
      government to its burden of proof at trial by denying the essential
      factual elements of guilt, is convicted, and only then admits guilt and
      expresses remorse. Conviction by trial, however, does not automatically
      preclude a defendant from consideration for such a reduction. In rare
      situations a defendant may clearly demonstrate an acceptance of
      responsibility for his criminal conduct even though he exercises his
      constitutional right to a trial. This may occur, for example, where a
      defendant goes to trial to assert and preserve issues that do not relate to
      factual guilt . . . . In each such instance, however, a determination that
      a defendant has accepted responsibility will be based primarily upon
      pre-trial statements and conduct.

USSG § 3E1.1 comment 2.


                                         -13-
       Johnston maintains that he only went to trial because he disputed the amount
of the methamphetamine the government attributed to him. He points to his statement
to police as proof that he admitted his conduct prior to the trial. Just because
Johnston cooperated, however, does not mean he is entitled to the acceptance of
responsibility adjustment. By disputing the amount of methamphetamine he was
responsible for, he put the government to its proof and challenged his factual guilt.
The district court was within its discretion to deny Johnston an adjustment for
acceptance of responsibility.

                                      Conclusion

       The district court acted within its discretion in refusing to declare a mistrial and
in sentencing Johnston to 210 months in prison. Accordingly, we affirm.

HEANEY, Circuit Judge, concurring.

       I am troubled by the fact that the district court used a drug quantity at
sentencing fifty times larger than the jury’s verdict. Notwithstanding considerable
evidence as to the substantial quantity of methamphetamine involved in this
conspiracy, the jury specifically found that Johnston was responsible for distributing
less than fifty grams. Under these circumstances, it is my feeling that the district
court should not be permitted to ignore the jury’s conclusion. The district court,
because of its ability to base its drug determination on a preponderance of the
evidence, has considerable discretion in sentencing, and the power to impose a
harsher sentence than a jury would on the same facts. By allowing the district court
to base drug quantity determinations using this lower level of proof, I believe the
stated goal of the Sentencing Guidelines – to promote uniformity in sentencing – is
undermined.

                        ______________________________

                                           -14-