UNPUBLISHED

UNITED STATES COURT OF APPEALS

FOR THE FOURTH CIRCUIT

UNITED STATES OF AMERICA,
Plaintiff-Appellee,

v.                                       No. 95-5425

CLARA MARSHALL LATTIN,
Defendant-Appellant.

Appeal from the United States District Court
for the Eastern District of Virginia, at Alexandria.
Albert V. Bryan, Jr., Senior District Judge.
(CR-508-A)

Submitted: February 18, 1997
Decided: March 21, 1997

Before HAMILTON, WILLIAMS, and MICHAEL, Circuit Judges.

_________________________________________________________________

Affirmed by unpublished per curiam opinion.
_________________________________________________________________

COUNSEL

Gordon Widenhouse, Assistant Federal Public Defender, Raleigh,
North Carolina, for Appellant. Helen F. Fahey, United States Attor-
ney, Jay Apperson, Assistant United States Attorney, Alexandria,
Vir-
ginia, for Appellee.

_________________________________________________________________
Unpublished opinions are not binding precedent in this circuit. See
Local Rule 36(c).
OPINION

PER CURIAM:

Clara Marshall Lattin appeals her convictions for conspiracy to
import heroin, 21 U.S.C. § 963 (1994), and conspiracy to distribute
and possess heroin with the intent to distribute, 21 U.S.C. § 846
(1994). Finding no reversible error, we affirm.

First, Lattin asserts the court abused its discretion by refusing
to
permit her to call Josette Breaux, an indicted co-conspirator, as
a wit-
ness for the sole purpose of impeaching her testimony. The Govern-
ment did not call Breaux to testify, but introduced testimony of
three
other indicted co-conspirators who implicated Lattin in their
heroin
trafficking operation. Lattin asked to call Breaux to establish
that she
would have lied had the Government called her to testify; addition-
ally, Lattin asserted that Breaux's impeachment would have
impeached the testimony of the co-conspirators who testified
against
her.

The court did not abuse its discretion because Lattin sought to
impeach a witness who did not testify for the Government. As the
court properly stated, "the Government is not going to call her, so
she
won't implicate your client . . . I am not going to let her be set
up just
to impeach her." While a party may impeach its own witness, the
dis-
trict court did not abuse its discretion here because the
Government
did not call Breaux to testify. See United States v. Morlang, 531
F.2d
183, 189-90 (4th Cir. 1975). We also note that Lattin fails to
establish
that Breaux's testimony went to the credibility of government wit-
nesses at all. Moreover, Appellant was permitted to argue to the
jury
that the credibility of the conspirators who testified should be
assessed in light of their plea agreements. Thus, the jury had
before
it evidence of possible biases of government witnesses and could
assess their credibility accordingly.

Second, Lattin asserts the district court committed plain error,
see
United States v. Olano, 507 U.S. 725 (1993), in instructing the
jury
about the existence of a conspiracy and about heroin's status as a
con-
trolled substance. Because the Constitution "gives a criminal
defen-
dant the right to have a jury determine, beyond a reasonable doubt,

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his guilt of every element of the crime with which he is charged,"
United States v. Johnson, 71 F.3d 139, 142 (4th Cir. 1995), a trial
court may not instruct the jury that a fact essential to conviction
has
been established by the evidence. Id.
The district court properly instructed the jury about          the
definition
of a conspiracy. Additionally, it instructed the jury that

     [i]f you conclude that the conspiracy did exist, you should
     next determine whether or not the defendant willfully and
     knowingly became a member of the conspiracy.

     And indeed, that latter is what the issue is in this case.
     While
     it is your recollection that counts, it does not seem to me
     that here is any real question but that [ ] there is a
     conspir-
     acy both to import and to possess with intent and to distrib-
     ute heroin. What the issue in the case is not whether there
     was a conspiracy, but whether this defendant willfully, will-
     fully became a member of that conspiracy.

Further, the court instructed the jury that they were the "sole
judges
of the facts" and "what the Court or the lawyers say to you
regarding
the evidence or their recollection of the evidence is not binding
on
you." Lattin asserts the court's instruction directed a verdict
about the
existence of a conspiracy.
The court also instructed the jury that the law"prohibit(s)
importa-
tion of a controlled substance . . . heroin is a controlled
substance."
Lattin asserts that this instruction was improper because heroin's
sta-
tus as a controlled substance was a question of fact for the jury
to
decide.

As to the conspiracy instruction, the district court did not commit
reversible error. It surrounded its comments about the existence of
a
conspiracy with instructions that the jury should decide the issue
itself. Thus, it did not preempt the jury from making any factual
deter-
mination. See United States v. Gravely, 840 F.2d 1156, 1164-65 (4th
Cir. 1988). As to the heroin instruction, the court did not commit
plain error because heroin is listed as a controlled substance in
21

     3
U.S.C. § 812(b) (1994), and the issue of whether it is a controlled
substance is an issue of law, not fact. See United States v.
Gonzales-
Palma, 645 F.2d 844, 846 (10th Cir. 1981).

Accordingly, we affirm Lattin's convictions. We dispense with oral
argument because the facts and legal contentions are adequately
pres-
ented in the material before the court and argument would not aid
the
decisional process.

AFFIRMED
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