                     United States Court of Appeals
                              FOR THE EIGHTH CIRCUIT

      __________

      No. 99-2890
      __________

United States of America,               *
                                        *
      Plaintiff - Appellee,             *
                                        *
      v.                                *
                                        *
Miguel Calderin-Rodriguez,              *
                                        *
      Defendant - Appellant.            *

      __________
                                            Appeals from the United States
      No. 99-2891                           District Court for the
      __________                            District of Nebraska.

United States of America,               *
                                        *
      Plaintiff - Appellee,             *
                                        *
      v.                                *
                                        *
Alberto Martinez-Mostelier,             *
                                        *
      Defendant - Appellant.            *

      __________

      No. 99-2892
      __________
United States of America,               *
                                        *
      Plaintiff - Appellee,             *
                                        *
      v.                                *
                                        *
Ricardo Gorrin,                         *
                                        *
      Defendant - Appellant.            *


      __________

      No. 99-3055
      __________

United States of America,               *
                                        *
      Plaintiff - Appellee,             *
                                        *
      v.                                *
                                        *
Ernesto Contreras-Silverio,             *
                                        *
      Defendant - Appellant.            *
                                   ___________

                              Submitted: May 8, 2000

                                  Filed: March 29, 2001
                                   ___________

Before McMILLIAN, JOHN R. GIBSON, and BEAM, Circuit Judges.
                            ___________

JOHN R. GIBSON, Circuit Judge.


                                        -2-
       Miguel Calderin-Rodriguez, Alberto Martinez-Mostelier, Ernesto Contreras, and
Ricardo Gorrin were each convicted of conspiracy to distribute cocaine,
methamphetamine, and/or amphetamine, in violation of 21 U.S.C. § 846 (1994). The
indictment named six other co-conspirators, five of whom pleaded guilty, and one of
whom has never been apprehended. Calderin-Rodriguez was sentenced to 225 months
imprisonment, Martinez-Mostelier to 178 months, Contreras to 92 months, and Gorrin
to 80 months. On appeal, the four argue1 that there was insufficient evidence of
conspiracy; that the district court2 erred in admitting audio tapes of drug transactions
and in allowing the jury to view transcripts of those tapes; that the court should have
stricken testimony of one of the government's witnesses because the government
violated the court's sequestration order; and that the court erred in imposing the
sentences. We reject these and various other arguments. We affirm the convictions
and sentences imposed.

      The appellants and their co-conspirators sold cocaine and methamphetamine,
operating principally out of two apartment buildings in the town of Hastings, Nebraska.
The indictment covered the period of August 1, 1996 through May 17, 1998. The
government's case consisted of testimony by undercover police and confidential
informants who made controlled purchases of drugs from the group, audio tapes of
those transactions, testimony by drug users who habitually bought drugs from the
group, and evidence seized during searches of the apartments. The government also
introduced the actual drugs purchased in the controlled transactions, as well as other
drugs found in a hotel room after Gorrin had stayed there.




      1
       Although the appellants have filed separate briefs, three of them have adopted
each others' arguments by reference.
      2
      The Honorable Lyle E. Strom, United States District Judge for the District of
Nebraska.

                                          -3-
       Kiley Bera gave the police entree to the drug world in Hastings. In late 1996 and
1997, she was in regular attendance at the apartment of Sammy Howell, a drug dealer
who lived down the street from her. At Howell's she encountered Miguel Calderin-
Rodriguez and Alberto Martinez-Mostelier, who came to Howell's about every day to
deliver an ounce or so of methamphetamine and to collect money from Howell for past
credit purchases. Later, she began to encounter Ignacio Ramirez at Howell's. Ramirez
was always there with either Calderin-Rodriguez or Martinez-Mostelier, or both, who
would often actually deliver the drugs to Howell and collect the money from him, but
who would turn the money over to Ramirez. Between January 1997 and November of
that year, Ramirez was at Howell's almost every day.

       Bera visited the apartment of Ramirez, Calderin-Rodriguez, and Martinez-
Mostelier at 309 North Lexington, and she saw Ramirez and Martinez-Mostelier in the
apartment with a scale and powder all over a table. Ramirez later moved to 315 North
Bellevue, #1, where he lived with Ricardo Gorrin; Bera visited Ramirez there regularly
from about October 1997 to April 1998, and she almost always saw methamphetamine
and methamphetamine transactions there. She named eight of Ramirez's customers, not
counting the other members of the conspiracy. Ramirez told her he didn't like to sell
small amounts, so he would front methamphetamine to Geovoni San Pedro Lopez and
Ernesto Contreras (who lived upstairs at 315 North Bellevue, #2), who would make the
smaller sales. Bera saw Ramirez with between $4,000 and $5,000 cash, and he told
her on different occasions that he was going out of town to pick up "crank" or "a
package."

      Bera also knew Gorrin; she once saw him sell some cocaine to a customer when
Ramirez wasn't home. Ramirez told Bera in February or March 1998 that he was angry
with Gorrin because Gorrin had fronted $3,000 worth of Ramirez's methamphetamine
to a woman.




                                          -4-
        Bera also testified about seeing Ramirez breaking up a large brick of
methamphetamine, then weighing and packaging it. He put the small amounts into a
plastic bag, then twisted the top and melted it with a lighter. Witness after witness
testified that the drugs they got from the members of the alleged conspiracy were
packaged in this way. Rita Hemmer, an experienced drug enforcement agent, said that
she had never seen this characteristic packaging in any other case.

        Another witness who bought drugs from the group was Clayton Smith, who
testified that he bought methamphetamine from Ramirez about twenty times at the
Bellevue apartment. Smith also bought from Martinez-Mostelier at 309 North
Lexington, which was known as "the office," and the methamphetamine was packaged
in the characteristic way already described. He bought cocaine and methamphetamine
from Martinez-Mostelier for about six months. Once, when he went to buy drugs from
Ramirez, Ramirez was not home, but Calderin-Rodriguez was there. Calderin-
Rodriguez left the apartment, walked in the direction of the office, and returned with
some methamphetamine for Smith, packaged in the characteristic way. Smith also
purchased methamphetamine and cocaine from Contreras in the same type packages.
At other times he bought from Gorrin when Ramirez was not home. Smith said Gorrin
acted as doorman. Smith said, "[I]t was pretty much a network thing there, you know,
if one didn't have it, they would point which way to go to whoever had it."

        Lisa Doyen was another regular drug purchaser who testified that she bought
methamphetamine from Calderin-Rodriguez, Ramirez, and Martinez-Mostelier. She
testified that she saw Calderin-Rodriguez sell methamphetamine to five to fifteen other
people.

      Jeremy King also testified that he and his friends bought methamphetamine and
cocaine from Martinez-Mostelier and Calderin-Rodriguez. On a couple of occasions,
when Martinez-Mostelier or Calderin-Rodriguez didn't have the drugs, they sent him
to Ramirez. Once, when King came to buy cocaine from Martinez-Mostelier and

                                          -5-
Calderin-Rodriguez, he was greeted with suspicion. Someone patted him down, and
Calderin-Rodriguez laid a gun on the table. Another time, after he bought some
methamphetamine from Calderin-Rodriguez, he complained that it looked short.
Another indicted co-conspirator, Leo Parra, gave King some methamphetamine out of
his pocket to make up for the underweight package.

       Charles Lahiff was yet another regular drug purchaser who testified about
goings-on at the office. He ran into Ramirez there and bought methamphetamine from
him frequently after that. He bought methamphetamine and cocaine from Calderin-
Rodriguez beginning in 1996 and from Martinez-Mostelier at about the same time.
Lahiff participated in nine controlled buys in cooperation with the police. He wore a
body wire that transmitted radio waves during these transactions. The police taped the
transmissions, and the government introduced the tapes into evidence. Participants in
the taped transactions with Lahiff included Calderin-Rodriguez, Contreras, and Gorrin,
as well as other indicted co-conspirators. Often, more than one conspirator was
involved in a single transaction. For instance, on May 1, 1998, Lahiff went to the
office to buy from someone who was not indicted in this case; he ended up actually
buying the drug from Contreras, but while Contreras was out picking up the
merchandise, Calderin-Rodriguez forced Lahiff to sniff cocaine. Later testimony
revealed that it is a common practice for drug dealers to make customers ingest drugs
in their presence to prove they are not cooperating with police.

      The two undercover police who participated in controlled buys were Rita
Hemmer and Tony Keiper.3 Hemmer made eleven purchases from members of the
conspiracy from October 14, 1997 to May 26, 1998. Hemmer was introduced to the
group by Bera, who accompanied her during eight of the transactions. For each


      3
       Keiper went along with Lahiff on one purchasing expedition, in which they
bought methamphetamine from a member of the conspiracy.


                                         -6-
transaction, either Bera or Hemmer wore a transmitter so that Officer Ron Gardner
could monitor the progress of the transaction and record it. Hemmer purchased
methamphetamine from each of the appellants in this case, and many of her purchases
involved cooperation between more than one of the appellants or between an appellant
and another indicted co-conspirator. For instance, on October 28, 1997, Hemmer and
Bera went to the office and ordered methamphetamine from Calderin-Rodriguez.
Martinez-Mostelier, who was also there, fetched the drugs from the bedroom and
delivered them to Hemmer. Similarly, on January 13, 1998, Hemmer and Bera went
to Martinez-Mostelier's residence (after he had moved from the North Lexington
apartment) and ordered methamphetamine. Martinez-Mostelier left for five to ten
minutes, and shortly after he returned, one of the other indicted co-conspirators arrived
with the drugs. Again, on March 25, 1998, Hemmer ordered a quantity of
methamphetamine from an indicted co-conspirator who did not have the drugs on hand.
He made a telephone call, speaking in Spanish,4 and Hemmer understood the word
"Neto." The co-conspirator sent her to the North Lexington building, where Contreras
delivered half the ordered amount of drugs and where Calderin-Rodriguez later arrived,
delivering the other half of the order. In the audio tape of the transaction with
Contreras, Hemmer asks, "Are you Neto?" and Contreras answers, "Yeah." This
pattern of cooperation among the appellants and other co-conspirators was remarked
upon during one of the taped conversations. Because Hemmer wanted more
methamphetamine than Ramirez had, she asked him if "those guys upstairs" had any.
Ramirez responded: "Nobody–when I don't got any, nobody got." Another time
Hemmer called Contreras looking for methamphetamine. Contreras had none, and he
told Hemmer that Ramirez had it all and that he, Contreras, got his drugs from Ramirez.

      There was also testimony from police who executed a search warrant at 315
North Bellevue, #2. They found Contreras, Martinez-Mostelier and others there.
There was methamphetamine in a coat that officers had seen Martinez-Mostelier

      4
          The appellants are Cubans, who communicated primarily in Spanish.

                                          -7-
wearing earlier. An officer who executed a search warrant at 315 North Bellevue, #1
and arrested Gorrin there testified that police found a scale, plastic bags, rubber gloves,
and other drug packaging equipment at the apartment.

      A housekeeper at a Hastings motel identified seven packets she found while
cleaning a room that had been registered to Gorrin the day before. The policeman to
whom she delivered the packages had the contents analyzed; the packets contained
cocaine.

                                            I.

      The appellants argue that there was insufficient evidence to show that they
entered a conspiracy. They say that the evidence only shows that they "may have been
involved in some illegal activity," but not that there was any sort of agreement.

      In reviewing a jury verdict, we examine the evidence in the light most favorable
to the government, giving the government the benefit of all favorable inferences.
Glasser v. United States, 315 U.S. 60, 80 (1942); United States v. Frayer, 9 F.3d 1367,
1371 (8th Cir. 1993). We can reverse for insufficiency of the evidence only if no
reasonable jury could have found the defendant was guilty beyond a reasonable doubt.
Frayer, 9 F.3d at 1371. A person who knowingly contributes his efforts to further the
criminal objects of a conspiracy will be deemed to have joined the conspiracy. Id.

       There was overwhelming evidence, which we have outlined above and which
would fill too many pages to retell in full, that the appellants in this case and others
charged in the indictment cooperated in the drug enterprise headed up by Ramirez. In
many, perhaps most, of the sales described, more than one alleged co-conspirator
contributed his efforts, with no hint that they were competing with each other for sales




                                           -8-
or that it made any difference to them whether one or the other of them sold the drug.5
Kiley Bera saw Calderin-Rodriguez and Martinez-Mostelier collect money and then
deliver it to Ramirez. If a customer approached one of them when he had no
merchandise, he would direct the customer to someone else in the group who had drugs
to sell. When Jeremy King complained that a purchase from Calderin-Rodriguez was
underweight, another alleged co-conspirator made up the shortfall with drugs from his
own pocket. Purchases from different members of the alleged conspiracy were all
packaged in the same characteristic way, with the melted plastic. Kiley Bera saw
Ramirez heat-sealing such packages. There was enough evidence to support the
conspiracy conviction.

                                         II.

      The appellants contend that the district court erred in refusing to strike the
testimony of witness Charles Lahiff because Lahiff discussed his testimony with the
prosecutor and another witness during the evening recess midway through his direct
testimony.

       Before trial the defendants requested that the witnesses be sequestered. The
court responded that such a request must be automatically granted under Federal Rule
of Evidence 615, "so our witnesses will be sequestered." The court further told
counsel, "I want you to instruct your witnesses that they're not to talk to each other
about their testimony. That goes for the government as well as for the defendants so–



      5
       There were occasional hints of discord among the members of the group. Once
Ramirez told a customer that the person upstairs (presumably Geovoni San Pedro
Lopez, an indicted co-conspirator) was stealing his customers and Ramirez wanted him
hurt. Bera reported that Ramirez was angry with Gorrin because he had given one
woman $3000 worth of Ramirez's drugs on credit. These incidents were extremely
minor in the context of all the testimony showing cooperation among the group.

                                          -9-
and, obviously, their witnesses are going to have to talk to counsel, but they should not
talk to each other about their testimony."

       Lahiff's testimony began late in the day of February 25, 1999, and had hardly
started when it was time for the evening recess. The next morning the Assistant United
States Attorney began by asking Lahiff whether he had thought over several aspects of
his testimony from the day before; Lahiff then corrected his testimony about which
police officers he had first worked with as a confidential informant, when he met
Ramirez, and other similar details, refreshing his recollection by referring to reports he
had prepared at the time of the events. Lahiff mentioned that, since his testimony the
day before, he had spoken to Glenn Kemp, the officer with whom he had first worked.
Throughout Lahiff's testimony, he had to refresh his recollection by referring to written
reports and other documents and listening to tapes. He said that he had been a heavy
user of methamphetamine and cocaine for the three-year period preceding April 1998,
taking between three and four grams per day of some combination of these drugs.
During cross-examination, counsel asked him about how he came to correct his
testimony, and Lahiff said that he had looked over his notes and met with Assistant
United States Attorney Gillan. "With Mr. Gillan's help I realized what I said was
wrong." Kemp testified immediately after Lahiff. The defendants moved to strike
Lahiff's testimony, and the court denied the motion.

       The appellants now contend not only that the district court erred in denying their
motion, but that the denial violated their Sixth Amendment right to confront the
witnesses against them by making their cross-examination of Lahiff less effective than
if he had not corrected his errors in advance of cross examination. There is no legal
support for their constitutional argument, but their claim of trial error must be analyzed
in detail.

       Appellants object more vociferously to the meeting between the prosecutor and
Lahiff than to that between Lahiff and Kemp, but the meeting between Lahiff and the

                                          -10-
prosecutor violated neither Federal Rule of Evidence 615 nor the sequestration order
in this case. Rule 615 provides simply: "At the request of a party the court shall order
witnesses excluded so that they cannot hear the testimony of other witnesses . . . ."
This rule does not by its terms forbid an attorney from conferring with witnesses during
trial. Cf. United States v. Kindle, 925 F.2d 272, 276 (8th Cir. 1991) (Rule 615 does
not require court to forbid contact between DEA case agent and witness during trial).
Nor is it inherently unethical for a lawyer to speak to a witness once the witness has
begun to testify. See United States v. De Jongh, 937 F.2d 1, 3 (1st Cir. 1991); 29
Charles Alan Wright and Victor James Gold, Federal Practice and Procedure § 6243,
at 64 (1997) ("During the course of a trial, an attorney customarily consults out-of-court
with his client and other witnesses."). Assuredly, the district court, in exercise of its
discretion in regulating the conduct of the trial, may impose restrictions on an attorney's
contact with witnesses during trial, not only to prevent unethical coaching, but also
simply to preserve the status quo during breaks in testimony. See, e.g., Perry v. Leeke,
488 U.S. 272, 281-84 (1989) ("It is a common practice for a judge to instruct a witness
not to discuss his or her testimony with third parties until the trial is completed."). In
this case, however, the district court's order explicitly assumed that the attorneys would
talk to witnesses.

      Even if the conference between counsel and Lahiff had been improper under the
sequestration order, the district court would still have wide latitude in deciding how to
respond to the impropriety. Kindle, 925 F.2d at 276; see United States v. Covington,
133 F.3d 639, 645 (8th Cir. 1998) (district court's response to improper communication
between witnesses reviewed for abuse of discretion). There is no convincing showing
of prejudice in this case, since it was obvious from Lahiff's testimony on the second day
that he was relying on the written reports to refresh his recollection; he was cross-
examined about the interview with Gillan; and even without the conference, the
government would likely have been able to help Lahiff correct his earlier testimony by
showing Lahiff the reports in court as prior inconsistent statements or to refresh his
recollection. Lahiff freely admitted that his drug use affected his memory, and he

                                           -11-
depended heavily throughout his testimony on written documents and tapes to refresh
his recollection. Moreover, the subjects on which Lahiff corrected himself were not
crucial, especially in view of the mountain of damaging evidence against the appellants.

       Lahiff's meeting with Glenn Kemp is of more concern, as it was clearly
prohibited by the district court's sequestration order telling the attorneys to keep their
witnesses from talking to each other about their testimony. However, the Assistant
United States Attorney voluntarily brought up the meeting during Lahiff's testimony
with no apparent consciousness of wrongdoing, and the appellants did not even cross-
examine Kemp or Lahiff on the subject. Without a showing of prejudice, the district
court did not abuse its discretion in refusing to strike Lahiff's testimony on the basis of
his meeting with Kemp.

       We therefore reject the appellants' contention that permitting Lahiff's testimony
constituted trial error. We also reject the appellants' assertion that the conference with
Lahiff entitled them to a mistrial on the ground of prosecutorial misconduct.

                                           III.

      Contreras contends that the indictment was duplicitous because it alleged
conspiracy to distribute cocaine, amphetamine, and methamphetamine, all in violation
of 21 U.S.C. § 841(a)(1) (1994). We rejected the same argument in United States v.
Moore, 184 F.3d 790, 793 (8th Cir. 1999), cert. denied, 120 S. Ct. 1174 (2000). In
Moore, as in this case, an indictment for conspiracy to distribute a controlled substance
alleged that the conspiracy involved more than one drug. We held: "Enumerating the
controlled substances did not render count I duplicitous." Id. The indictment was not
duplicitous.




                                           -12-
                                           IV.

       Much of the strength of the government's case came from audio recordings made
by Officer Ron Gardner as he monitored the undercover drug purchases. The
undercover agents and confidential informants wore body wires that transmitted radio
signals while they were buying drugs from the members of the conspiracy. Officer
Gardner testified that he waited in a car near the apartments where the transactions
took place, listening to the transmitted conversations and recording them on a cassette
tape recorder. Gardner had successfully used this equipment on thirty to forty earlier
occasions, and he checked his equipment each time before he used it. He also listened
to each tape recording after the transaction. Gardner testified that when he listened to
the tapes, there were no additions or deletions to the tape recordings and that they
appeared to be in the same condition at trial as when he had made them. Kiley Bera,
Rita Hemmer, Tony Keiper, and Charles Lahiff, the participants in the recorded
conversations, testified at trial and were available for cross-examination. Keiper,
Hemmer, or Lahiff testified about the substance of each conversation for which a tape
was introduced.

       Because the conversations were partly in Spanish, the government retained Jeck-
Jerard Navarette, a translator, who enhanced the tapes by using a software program to
reduce background noise and increase the volume of the speech. Navarette had
performed this digital enhancement more than fifty times, and he testified that it did not
add or subtract anything to the tapes, but merely modified the volume in order to make
the words more intelligible. Navarette, working together with the agents and
informants, listened to the digitally enhanced recordings many times to make a
transcript of the words spoken, to translate the Spanish into English, and to identify the
speakers when possible. The court allowed the jury to look at the transcripts as an aid
while they were listening to the tapes, but did not allow the jury to have the transcripts
during deliberation.


                                          -13-
         Gorrin argues that the admission of the digitally enhanced recordings was error
because the court should have required a Daubert6 hearing to lay the foundation for the
tapes as scientific evidence. We have not required as a foundation for admission of
tapes into evidence that an expert testify how tape recorders work. Instead, in United
States v. McMillan, 508 F.2d 101, 104 (8th Cir. 1974), we set out seven foundational
requirements for admission of tapes, some of which depend on evidence that the
machine does work, but none of which require that the witness understands the
scientific principles involved in tape recording. We see no distinction between the
foundation required for the tape recorder and that for the digital enhancement program,
which, from the point of view of a listener, simply improves the quality of the
recording. If the capacity for digital enhancement were built into the tape recorder
itself, rather than a separate step being required, the admissibility of the resulting tapes
would clearly be governed by McMillan. There is nothing in the use of this separate
device that should change our analysis.

       The first requirement of McMillan, "that the recording device was capable of
taking the conversation now offered in evidence," id., was amply satisfied in this case
by testimony that Navarette had listened to the tapes before and after enhancement and
he found the enhanced version to be "considerably more audible." See United States
v. McCowan, 706 F.2d 863, 865 (8th Cir. 1983) (per curiam) ("The very fact that the
tape recordings exist establishes that the recording device was capable of picking up
sounds and taking the conversation offered."); United States v. Roach, 28 F.3d 729,
733 (8th Cir. 1994). Navarette's testimony that he had successfully used the software
program about fifty times in the past also bolsters the conclusion that the program
worked. The second requirement, that the operator of the device was competent to
operate it, was satisfied by the same evidence. See McCowan, 706 F.2d at 865.
("Howard testified that he learned how to use the recorder on the day he made the
tapes. This fact, and the fact that Howard successfully made the tape recordings,

       6
           Daubert v. Merrell Dow Pharms., Inc., 509 U.S. 579 (1993).

                                           -14-
satisfied the competency requirement of the second element of the McMillan test.")
The third and fourth McMillan requirements, that the recording is authentic and correct
and that no changes, additions or deletions have been made, add a significant guarantee
of trustworthiness. In this case, these requirements have been satisfied by the
testimony of Officer Gardner, who listened to the original radio transmissions, that the
tapes were accurate portrayals of the conversations. Although technically a "change"
has been made by the digital enhancement, Navarette testified that it only changed the
volume of sounds. Volume adjustment is commonly used in playing back recordings
and is not legally significant. There is no dispute about the remaining McMillan
requirements. We therefore conclude that there was an adequate foundation for
admission of the tapes.

        Contreras argues that the court erred in allowing the jury to look at transcripts
which contained voice identifications and date headings. One of the principal reasons
for having a transcript is to help identify the speakers on the tape. McMillan, 508 F.2d
at 105. The foundation for the voice identifications and headings was established by
testimony of the participants in the conversations and Officer Gardner. The district
court carefully complied with our instructions in McMillan by only allowing the jury
to look at the transcripts as the tapes were played in the courtroom and by cautioning
the jury: "The tapes in this case are what you should be relying on. If for some reason
as you listen you think that what you hear is different than what's on the transcript, then
you should adopt what's on the tape." Nor have the appellants directed us to any errors
in the transcripts' voice identifications or date headings. See United States v. Britton,
68 F.3d 262, 264 (8th Cir. 1995) (without specific allegations of error, we must assume
transcript accurate). The use of the transcripts was not an abuse of discretion.

       Martinez-Mostelier contends that the tape of the transaction on January 13, 1998
should not have been admitted because there is a gap on the tape and because portions
of the tape are inaudible. The transcript shows the gap with the word "BREAK."
Officer Gardner testified that he blew a fuse in the car where the recorder was plugged

                                           -15-
in and lost power until he could change the fuse. Rita Hemmer, who participated in the
January 13 transaction, testified about what was said during the transaction, and both
she and Kiley Bera were available for cross examination about what happened during
the gap. Furthermore, review of the transcript indicates that the participants and
translator were able to make out a great deal of what was said, and the inaudible
portions did not render the tape as a whole untrustworthy. See United States v. Huff,
959 F.2d 731, 737-38 (8th Cir. 1992). The district court did not abuse its discretion
in admitting this tape. See id. (standard of review is abuse of discretion).

                                            V.

       Contreras contends that the district court erred in refusing to sever his case from
the other appellants'. Denial of a motion for severance is reviewed only for abuse of
discretion, resulting in definite prejudice. United States v. Delpit, 94 F.3d 1134, 1143
(8th Cir. 1996). Joinder is favored for conspiracy cases, United States v. Mercer, 853
F.2d 630, 632 (8th Cir. 1988), and there is no showing any of the appellants were
prejudiced by joint trial in this case.

                                            VI.

       The appellants raise various sentencing arguments. Martinez-Mostelier argues
that the district court erred in its calculation of the amount of drugs attributable to him,
and Contreras argues that the court erred in giving him a two-level enhancement for
possession of a gun in connection with the drug offense. Calderin-Rodriguez makes
both these arguments. The questions of what quantity of drugs was attributable to a
defendant and whether possession of a gun was sufficiently connected to a drug offense
to warrant enhancement under U.S.S.G. § 2D1.1(b)(1) are questions of fact, reviewable
only for clear error. United States v. Fairchild, 122 F.3d 605, 614 (8th Cir. 1997)
(gun); United States v. Smith, 49 F.3d 362, 365 (8th Cir. 1995) (drug quantity).


                                           -16-
       Under U.S.S.G. § 2D1.1(b)(1), a defendant's base offense level is increased by
two levels "[i]f a dangerous weapon (including a firearm) was possessed." "The
adjustment should be applied if the weapon was present, unless it is clearly improbable
that the weapon was connected with the offense." Id., comment. (n.3). The
government bears the burden of showing that a weapon was present and that it is not
clearly improbable that the weapon was connected with the crime. United States v.
Belitz, 141 F.3d 815, 817 (8th Cir. 1998).

       Police searching Contreras's apartment at 309 North Lexington, #9 discovered
a 25-caliber semiautomatic handgun under his mattress. The magazine was out of the
gun and contained five rounds of ammunition. Contreras objected to enhancement of
his offense level for possession of this gun. After a hearing, the district court found that
the increase was warranted by the evidence, and this finding is not clearly erroneous.

        Calderin-Rodriguez also contends that he should not have received an increase
for possession of a gun. The district court relied on the testimony of Jeremy King at
trial that once when he went to buy drugs from Calderin-Rodriguez, he was searched
and Calderin-Rodriguez had a gun in his hand. Calderin-Rodriguez argues that this
testimony is not trustworthy because no one else corroborated it. However, none of the
people King said were present at the time of the incident testified at trial. So if there
is no corroboration, neither is there any contrary evidence. The district court recounted
the details in King's testimony about the kind of gun Calderin-Rodriguez had, which
apparently convinced the court that the incident really happened. The court's finding
is not clearly erroneous.

       Calderin-Rodriguez attacks the district court's finding that at least five kilograms
of methamphetamine were attributable to him. He particularly attacks King's testimony
that Calderin-Rodriguez had a five- to- six pound chunk of methamphetamine. The
district court did not take this weight at face value, but stated that the weight of the
chunk must have been at least one kilogram. The district court also considered

                                           -17-
Calderin-Rodriguez's argument that other witnesses' estimates of drug amounts were
excessive, but found that, "I get to five kilograms very quickly, even discounting some
of the testimony." Calderin-Rodriguez asks us to discard the district court's credibility
determinations, but it is clear from the sentencing transcript that those determinations
were cautious and well-supported.

        Martinez-Mostelier also attacks the findings on drug amount, but the transcript
of his sentencing shows that the district court carefully considered his objections to
various witnesses' testimony and still found Martinez-Mostelier was responsible for at
least five kilograms of methamphetamine:

      I've not only reviewed my trial notes, but I have also reviewed portions
      of the transcript of the testimony of Kiley Bera and Jeremy King, Clayton
      Smith and some of the others. Even discounting all of their testimony, it
      seems to me that there isn't any question that the amount of
      methamphetamine that was involved and which is reasonably chargeable
      to this defendant exceeds five kilograms.

The district court's finding is not clearly erroneous.

      We affirm the appellants' convictions and the sentences imposed.

      A true copy.

             Attest:

                 CLERK, U.S. COURT OF APPEALS, EIGHTH CIRCUIT.




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