                          PUBLISHED

UNITED STATES COURT OF APPEALS
                FOR THE FOURTH CIRCUIT


UNITED STATES OF AMERICA,              
                 Plaintiff-Appellee,
                 v.
                                                No. 05-4111
ERIC BERNARD SMITH, a/k/a E, a/k/a
Pac-Man, a/k/a Sld Dft 5:03CR12-2,
               Defendant-Appellant.
                                       
           Appeal from the United States District Court
     for the Western District of North Carolina, at Statesville.
              Richard L. Voorhees, District Judge.
                            (CR-03-12)

                      Argued: March 15, 2006

                      Decided: June 13, 2006

    Before MICHAEL, KING, and GREGORY, Circuit Judges.



Affirmed by published opinion. Judge King wrote the opinion, in
which Judge Michael and Judge Gregory joined.


                            COUNSEL

ARGUED: Aaron Edmund Michel, Charlotte, North Carolina, for
Appellant. Amy Elizabeth Ray, Assistant United States Attorney,
OFFICE OF THE UNITED STATES ATTORNEY, Asheville, North
Carolina, for Appellee. ON BRIEF: Gretchen C. F. Shappert, United
States Attorney, Charlotte, North Carolina, for Appellee.
2                       UNITED STATES v. SMITH
                              OPINION

KING, Circuit Judge:

   Eric Bernard Smith appeals his convictions by a jury in the West-
ern District of North Carolina on two related charges — conspiracy
to possess with intent to distribute cocaine and cocaine base (21
U.S.C. § 846), and possession with intent to distribute cocaine base
(21 U.S.C. § 841(a)(1)) — as well as his resulting sentence. Smith
makes multiple contentions of error, including (1) that his motion for
judgment of acquittal should have been granted because the jury ver-
dict on the conspiracy charge was not sufficiently supported by the
evidence, (2) that he should have been awarded a new trial, and (3)
that the enhancement of his sentence under 21 U.S.C. § 851 was
unconstitutional and erroneous. As explained below, we find no
reversible error and affirm.

                                   I.

                                  A.

   On February 25, 2003, Smith and eleven others were indicted
together in the Western District of North Carolina on a total of sixteen
drug-related counts. The first count of the indictment charged all
twelve defendants — including Smith and Edward Monroe Little —
with involvement in a conspiracy to distribute cocaine and cocaine
base (commonly known as "crack" or "crack cocaine") in Iredell,
Catawba, and Burke Counties of western North Carolina, from Janu-
ary 1995 until February 2003 ("Count One"). More specifically,
Count One charged that the defendants conspired to possess with
intent to distribute over fifty grams of crack cocaine and over five
kilograms of cocaine, in violation of 21 U.S.C. § 846. Additionally,
the third count of the indictment charged Smith with possession with
intent to distribute crack cocaine in Catawba County on October 19,
2001, in violation of 21 U.S.C. § 841 ("Count Three"). After the
indictment was returned, the prosecution filed an information, pursu-
ant to 21 U.S.C. § 851, seeking to enhance Smith’s sentence on the
basis of his prior felony convictions: four drug felonies in June 1996
and three drug felonies in October 1997. On April 16, 2004, Smith
filed a motion to sever his trial from that of his co-defendant Little,
                        UNITED STATES v. SMITH                         3
contending that a joint trial would result in unfair prejudice. The dis-
trict court denied the severance motion and proceeded to try Smith
and Little together.

   The trial proceedings against Smith and Little began on May 4,
2004, in Statesville, North Carolina. During voir dire in the jury selec-
tion proceedings, the prospective jurors were asked whether they
could be fair and impartial. Prospective juror Joy Stutts initially
replied that she did not "know if I’d be fair or not because I’ve never
— I’m a housewife. I stay at home all the time and I don’t know any-
thing about any of this." S.J.A. 24.1 When asked whether she could
listen to testimony, examine evidence, "decide what the facts are and
apply the law that the judge gives you," she initially replied, "I’m not
sure." Id. Smith moved to have Stutts excused from the jury venire
for cause, but the court denied the motion. On further questioning,
Stutts answered that she "would try to be" fair but that she "couldn’t
promise." Id. at 26. The Assistant United States Attorney continued
to question her as follows:

      Q: Well, do you know of any reason that you couldn’t be
      fair?

      A: No.

      Q: Okay. Do you have any moral or religious problems
      following the law?

      Q: Do you have any problems taking an oath that you’ll
      follow the law?

      A: No.

Id. at 27. When Smith’s defense lawyer renewed his motion to excuse
Stutts for cause, the court again denied the motion, explaining that
Stutts had sufficiently confirmed that she would be fair. The jury, as
ultimately selected, included Stutts.
  1
   Citations to "S.J.A. ___" refer to the contents of the Supplemental
Joint Appendix filed by the parties in this appeal.
4                      UNITED STATES v. SMITH
                                 B.

   During the four-day trial, the prosecution presented extensive evi-
dence of Smith’s involvement in a long-running drug business cen-
tered in "The Hill" neighborhood of Newton, in Catawba County,
North Carolina. Fred Shuford testified that he had sold crack cocaine
to Smith in 1994 and 1995, at which point Smith stopped using drugs
and started selling them. Shuford then supplied Smith with progres-
sively increasing amounts of crack cocaine for resale. Tony Young
testified that he had purchased crack from Smith three times in 2000,
totalling roughly 630 grams. On the third crack deal, Smith travelled
to Florida to obtain half a kilogram of crack for Young, which was
later distributed by Young and an associate on The Hill.

   Several of the defendants named in the indictment made plea deals
with the Government and testified against Smith and Little. Jamario
Emonite Allred testified that Smith worked for him in The Hill neigh-
borhood in the early 1990s as a "runner," in exchange for drugs, and
that Allred had observed Little make numerous drug sales on The Hill
in 1994 and 1995. Allred also stated that he had purchased crack
cocaine from Smith for resale during 1999 and 2000. Camron Pope
testified that he had purchased crack for resale from Smith in 2001,
and that he (Pope) twice sold Smith an ounce of crack in 2003. War-
ren England testified that he had purchased crack cocaine from Smith
from the mid-1990s until 2000, and again in 2002. Earnest Edward
Squarles, Jr. said that he had twice purchased crack from Smith, in
2000 or 2001, and that he saw Little with some of Smith’s associates
(co-defendants England and Sherwood Milas Gaither) in locations
where Smith, Squarles and others would distribute drugs.

   Jermaine Anthony, a prosecution witness who was not a co-
defendant, testified that Smith and Little had supplied him with drugs
for resale from 1996 or 1997 through 2000. On cross-examination,
Smith’s lawyer asked Anthony if he had been involved in a 1999
shooting incident, but Anthony denied being present when the shoot-
ing occurred. Smith’s lawyer continued to press Anthony on the point,
attempting to expose his possible bias against Smith — that is, that
Anthony had agreed to testify in exchange for favorable treatment
from the prosecution. The court curtailed Smith’s follow-up questions
on the issue, however, ruling the alleged shooting to be irrelevant to
                        UNITED STATES v. SMITH                         5
the Count One conspiracy offense, and noting that Anthony’s testi-
mony concerning the shooting would be hearsay because he indicated
that he had no personal knowledge of the event.

   In addition to these witnesses, the prosecution presented the evi-
dence of several law enforcement officers and forensic scientists.
Newton police officers testified about the facts underlying the allega-
tions against Smith in Count Three: On October 19, 2001, Smith was
arrested by Newton police, who seized from him 3.6 grams of crack
cocaine, packaged for distribution, as well as 1.5 grams of powder
cocaine and more than $2,300 in cash. Forensic chemist Lisa Edwards
of the North Carolina State Bureau of Investigation (the "SBI") testi-
fied that the seized substances tested positive for crack cocaine and
cocaine, respectively.

   In addition, several officers from the Hickory and Newton police
departments, as well as SBI forensic technicians, testified to other acts
underlying the conspiracy charge in Count One. For example, on
August 26, 1995, Smith had been arrested by Newton police, who
seized 5.4 grams of a substance from him (the "1995 Arrest"). Glenn
Parham, an SBI forensic chemist, testified that lab tests determined
the substance to be crack cocaine. On October 29, 2000, Smith had
been arrested by Hickory police, who seized .1 gram of a substance
from him (the "2000 Arrest"). Sgt. Brian Adams of the Hickory
Police Department testified that, when he stopped Smith on that occa-
sion, he obtained Smith’s consent for a search and found what
appeared to be a plastic bag of crack cocaine in Smith’s mouth. When
Smith attempted to swallow the bag, Adams forced him to spit out a
flake of its contents. An SBI expert testified that the seized flake con-
tained less than .1 gram of crack cocaine.

   During the testimony of these officers, it was revealed to the jury
that the physical drug evidence from the 1995 and 2000 Arrests had
been destroyed pursuant to police department procedures — the 5.4
grams had been destroyed by the Newton police after Smith pleaded
guilty in state court in 1996, and the .1 gram had been destroyed in
2003 by the Hickory police after the state court case against Smith
was dropped by prosecutors in 2002. Smith’s lawyer objected to the
introduction of any testimony regarding the drug evidence that had
been destroyed, and the prosecution countered by moving in limine
6                       UNITED STATES v. SMITH
to preclude defense questioning of the prosecution’s witnesses about
the destruction of the drug evidence, other than to elicit the fact that
it had been destroyed. The court granted the prosecution’s request and
denied Smith’s objections, explaining that Smith’s desire to cross-
examine the prosecution witnesses regarding the destruction of the
drug evidence was outweighed by the tendency of such questioning
to be confusing, prejudicial, and irrelevant.

   In a hearing on the issue, conducted outside the presence of the
jury, the court permitted Smith to voir dire the officers about the drug
evidence that had been destroyed. When Smith moved again to sup-
press all testimony relating to the destroyed evidence, the district
court again rejected his request, finding that there was "no evidence
of bad faith in terms of the handling of the evidence or the execution
of the policies concerning it." J.A. 295.2

                                  C.

   At the close of the prosecution’s case-in-chief, Smith unsuccess-
fully moved for judgment of acquittal on Counts One and Three, con-
tending that the evidence did not establish the "grand conspiracy
alleged in [Count One of] the indictment," and that there was no evi-
dence that the drugs allegedly seized from Smith on October 19, 2001
were possessed with intent to distribute. J.A. 312-14. The defense pre-
sented no evidence, and the issues were presented to the jury on May
10, 2004, for resolution. The jury returned a guilty verdict later that
day against Smith on Counts One and Three, but found in a special
verdict that the conspiracy in Count One involved only a detectable
amount of cocaine — not the five or more kilograms alleged in the
indictment. The jury also found by its special verdict that the conspir-
acy charged in Count One involved the distribution of at least fifty
grams of a mixture containing a detectable amount of crack.

   On May 17, 2004, Smith filed a motion for a new trial and renewed
his motions for judgment of acquittal on both convictions. Smith
asserted that there was insufficient evidence to establish either the
existence of the conspiracy alleged in Count One, or that Smith
    2
    Citations to "J.A. ___" refer to the contents of the Joint Appendix
filed by the parties in this appeal.
                        UNITED STATES v. SMITH                         7
intended to distribute crack cocaine as alleged in Count Three. On
June 22, 2004, the district court denied both motions. United States
v. Smith, No. 03-12, slip op. at 2 (W.D.N.C. June 22, 2004).

   During his sentencing proceedings, Smith objected to any sentenc-
ing enhancement based on his prior felony convictions, premising his
challenges on the applicability of 21 U.S.C. § 851. Smith contended
alternatively that (1) § 851 is unconstitutional, and (2) that the prose-
cution had failed to establish that his 1996 and 1997 convictions had
occurred prior to the Count One conspiracy. On January 10, 2005, the
court rejected Smith’s contentions with regard to the enhancement
and sentenced him to life in prison on Count One and 360 months on
Count Three (to run concurrently with the life sentence). On January
11, 2005, Smith filed his notice of appeal, and we possess jurisdiction
pursuant to 28 U.S.C. § 1291.

                                   II.

   We review de novo a district court’s denial of a motion, made pur-
suant to Rule 29 of the Federal Rules of Criminal Procedure, for judg-
ment of acquittal. United States v. Alerre, 430 F.3d 681, 693 (4th Cir.
2005). In conducting such a review, we are obliged to sustain a guilty
verdict if, viewing the evidence in the light most favorable to the
prosecution, the verdict is supported by "substantial evidence." United
States v. Burgos, 94 F.3d 849, 862 (4th Cir. 1996) (en banc) (citing
Glasser v. United States, 315 U.S. 60, 80 (1942)). We have defined
"substantial evidence" as "evidence that a reasonable finder of fact
could accept as adequate and sufficient to support a conclusion of a
defendant’s guilt beyond a reasonable doubt." Id.

   We review for abuse of discretion a district court’s denial of a
motion, made pursuant to Rule 33 of the Federal Rules of Criminal
Procedure, for a new trial. United States v. Perry, 335 F.3d 316, 320
(4th Cir. 2003). Under the applicable legal principles, a trial court
"should exercise its discretion to award a new trial sparingly," and a
jury verdict is not to be overturned except in the rare circumstance
when the evidence "weighs heavily" against it. Id. (internal quotation
marks omitted). Finally, we review for abuse of discretion the eviden-
tiary rulings made by a trial court. United States v. Hedgepeth, 418
F.3d 411, 419 (4th Cir. 2005).
8                       UNITED STATES v. SMITH
                                  III.

   By this appeal, Smith raises multiple issues concerning (1) the dis-
trict court’s denial of his request for judgment of acquittal on the con-
spiracy charge in Count One, (2) the court’s denial of his request for
a new trial, and (3) the court’s enhancement of his sentence under 21
U.S.C. § 851. We address these issues in turn.

                                   A.

   Smith first contends that the district court improperly denied his
motion for judgment of acquittal on Count One.3 In that regard, he
maintains that the evidence was insufficient to prove beyond a reason-
able doubt that: (1) he had resumed participation in The Hill drug dis-
tribution conspiracy after his release from state prison in 1999; and
(2) the illegal activity shown by the evidence constituted a single con-
spiracy, as opposed to separate, multiple conspiracies.

   In assessing whether a guilty verdict is sufficiently supported by
the evidence, we are cognizant that the "jury, not the reviewing court,
weighs the credibility of the evidence and resolves any conflicts in the
evidence presented." United States v. Burgos, 94 F.3d 849, 862 (4th
Cir. 1996) (en banc) (internal quotation marks omitted). And, in con-
ducting such a review, we are obliged to view the evidence and all
reasonable inferences to be drawn therefrom in the light most favor-
able to the prosecution. United States v. Perry, 335 F.3d 316, 320 (4th
Cir. 2003).

                                   1.

   Smith spent a substantial part of 1998 and 1999 in state prison on
various drug convictions. He essentially contends that he withdrew
from the Count One conspiracy when he was incarcerated by the State
and, when released from state prison in 1999, he did not rejoin the
conspiracy. Thus, he asserts, because he withdrew from the conspir-
acy more than five years before the indictment was returned (Febru-
    3
   On appeal, Smith has abandoned his claim that he was entitled to a
judgment of acquittal on Count Three.
                          UNITED STATES v. SMITH                            9
ary 25, 2003), his prosecution on Count One was barred by the five-
year statute of limitations established in 18 U.S.C. § 3282(a). Unfor-
tunately for Smith, there was ample evidence at trial to support the
jury’s conclusion that he actively participated in a drug distribution
conspiracy with others in The Hill neighborhood after his release
from prison in 1999. For example, Pope purchased various quantities
of crack cocaine from Smith in 2001, 2002, and 2003; Young and
Squarles bought crack from Smith in 2000 or 2001; and Allred pur-
chased crack from Smith in 1999 and 2000. In addition, narcotics
officers in Hickory and Newton seized crack cocaine and large sums
of cash from Smith in 2000 and 2001. Given the evidence presented
at trial, the court did not err in declining to award Smith a judgment
of acquittal on this basis.4

                                     2.

   Moreover, the evidence was more than sufficient to permit the jury
to conclude that the illegal activities of the conspirators constituted a
single conspiracy rather than separate, multiple conspiracies. Under
the applicable principles, trial evidence is sufficient to establish a sin-
gle conspiracy where the conspirators are shown to share the same
objectives, the same methods, the same geographic spread, and the
same results. See United States v. Pratt, 351 F.3d 131, 140 (4th Cir.
2003); United States v. Crockett, 813 F.2d 1310, 1317 (4th Cir. 1987).
Here, the evidence, viewed in the proper light, established that The
Hill drug distribution ring involved the same core participants (Smith,
Little, and their other co-conspirators) over the same time period
(1995 to 2003).5 And these conspirators were shown to have shared
  4
     Smith asserts that the court erred in failing to instruct the jury on the
statute of limitations issue on the Count One conspiracy. Because Smith
failed to request any such instruction at trial our review is for plain error.
See United States v. Matzkin, 14 F.3d 1014, 1017 (4th Cir. 1994). As
explained above, the evidence demonstrated that Smith had participated
in the conspiracy within five years of the indictment, and there was no
plain error in this respect.
   5
     Prosecution witness Shuford testified that Smith began selling crack
cocaine that he purchased from Shuford in 1995. Anthony testified that
he started buying crack from Smith in 1996 or 1997, in amounts that
escalated over the years to three ounces in 2000. England purchased
crack from Smith throughout the mid-1990s.
10                       UNITED STATES v. SMITH
the same objectives and methods: distributing crack in The Hill neigh-
borhood for profit. The prosecution presented substantial evidence to
the jury of coordinated transactions between the various conspirators,
directed to this objective. For example, Squarles testified that, in 2000
and 2001, he had purchased from Smith several quantities of crack
cocaine valued at $300 that he would then resell for $600. He would
then use those funds to purchase additional crack to sell and distribute
on The Hill. Under the evidence before it, the jury was entitled to
conclude that the actions of the various participants in these illegal
activities amounted to a single conspiracy, and the court thus properly
denied Smith’s motion for judgment of acquittal on Count One.6

                                    B.

   Next, Smith makes five primary contentions in support of his asser-
tion that the district court abused its discretion in denying his motion
for a new trial.7 These contentions are: (1) that the court erred in its
denial of his severance motion; (2) that it improperly denied his
request to excuse juror Stutts for cause; (3) that it erroneously circum-
scribed his cross-examination of witnesses on the destruction of drug
evidence seized in his 1995 and 2000 Arrests; (4) that the court erred
in permitting the testimony of witnesses who lacked sufficient per-
sonal knowledge; and (5) that it improperly circumscribed his cross-
examination of witness Anthony. We assess these five new trial con-
tentions in turn.

                                     1.

   First, Smith asserts that the district court improperly denied his
motion to sever his trial from that of his co-defendant Little. As a gen-
eral principle, when defendants have allegedly participated in the
same acts or transactions, they may be indicted and tried jointly. See
Fed. R. Crim. P. 8(b); United States v. Williams, 10 F.3d 1070, 1079-
  6
     Smith does not contend that any instructions on this single conspiracy
issue were somehow defective.
   7
     Smith also contends that he is entitled to a new trial because the dis-
trict court failed to instruct the jury on the statute of limitations issue
relating to the Count One conspiracy. As discussed supra note 4, that
contention is meritless.
                        UNITED STATES v. SMITH                        11
80 (4th Cir. 1993). If a particular defendant can show that his trial
joinder with a co-defendant would prejudice his right to a fair trial,
however, the trial court may, in its discretion, grant a severance. See
Fed. R. Crim. P. 14(a); Williams, 10 F.3d at 1080. Assuming that a
joinder of two or more defendants for trial was proper in the first
instance, we will not overturn the trial court’s denial of a severance
motion, unless an appellant can show that the joint trial resulted in a
"miscarriage of justice." Williams, 10 F.3d at 1080.

   In these circumstances, the joinder of Smith and Little’s trial was
proper in the first instance, and the court did not err in refusing
Smith’s request for a severance. Count One charged, and the evidence
established, that Smith and Little had dealt drugs over the same period
of time in The Hill neighborhood, buying from the same suppliers and
selling to the same customers. Indeed, a substantial portion of the trial
evidence went directly to showing Smith’s guilt on the offenses
charged. Because Smith is unable to show that the challenged joinder
resulted in a miscarriage of justice, the denial of his motion for a sev-
erance was not an abuse of the trial court’s discretion.

                                   2.

   Smith next contends the district court erred in its denial of his new
trial request because juror Stutts should have been excused from the
venire for cause. Smith maintains that his challenge for cause was
meritorious because Stutts’s responses on voir dire demonstrated her
inability to fairly evaluate the evidence and apply the law in his case.

   It is well-settled, of course, that an accused is entitled under the
Sixth Amendment to trial by a jury composed of those who will
adhere to the law and fairly judge the evidence. See United States v.
Turner, 389 F.3d 111, 117 (4th Cir. 2004); see also Conner v. Polk,
407 F.3d 198, 205 (4th Cir. 2005). Although Stutts indicated some
hesitancy in her initial voir dire responses, the overall context of her
questioning confirmed that she would understand the trial proceed-
ings, that she would listen to the evidence and apply the law, and that
she could be fair to both sides. Indeed, she asserted that she had no
problem taking an oath, nor any moral or religious objections against
following the law. In these circumstances, we must defer to the sound
12                      UNITED STATES v. SMITH
judgment of the trial court, which did not abuse its discretion in deny-
ing a new trial on this basis. See Turner, 389 F.3d at 117.

                                   3.

   As his third basis for his claim that he was entitled to a new trial,
Smith contends that the district court erred in restricting his cross-
examination of law officers concerning their destruction of drug evi-
dence seized from Smith in the 1995 and 2000 Arrests. As explained
below, although the court’s limitations on cross-examination were
erroneous, the error was, in the circumstances, harmless.

                                   a.

   As noted, Smith sought to suppress — and repeatedly interposed
objections to — the admission of the drug evidence seized during his
1995 and 2000 Arrests, after it became apparent that the drug evi-
dence had been destroyed by the Hickory and Newton police depart-
ments. When Sergeant David Sigmon testified that 5.4 grams of
cocaine had been seized from Smith in 1995 by the Newton police,
he acknowledged that the seized drugs could not be presented at trial
because they had been destroyed. As a result, the court permitted
Smith to voir dire Sigmon on the circumstances surrounding the evi-
dence’s destruction. Sigmon said that the evidence had been
destroyed pursuant to routine procedures after Smith entered a guilty
plea to a related state offense in 1996. Although the Newton authori-
ties were unable to locate their records on the evidence’s destruction,
Sigmon explained that, when the evidence was destroyed, neither he
nor his department had been aware of any pending investigations or
charges concerning Smith; otherwise, the evidence would have been
retained.

    Smith also sought to suppress the drug evidence seized during his
2000 Arrest in Hickory. In that regard, Officer Adams of Hickory tes-
tified that the flake of crack cocaine he had seized from Smith’s
mouth on that occasion had also been destroyed. In anticipation of
Smith’s desire to cross-examine Adams on this point, the prosecution
proffered that Adams would testify that the drug evidence had been
destroyed "consistent with Hickory Police Department’s procedures
and policies," after the state prosecutors determined not to pursue
                        UNITED STATES v. SMITH                        13
charges related to the 2000 Arrest. S.J.A. 290. The prosecution
requested that the court preclude Smith’s lawyer from cross-
examining its witnesses regarding the destruction of the drug evi-
dence seized in the two arrests, beyond the fact that it had been
destroyed consistent with police procedures. Smith resisted this limi-
tation, contending that the jury, having heard that drugs had allegedly
been seized from Smith in 1995 and 2000, was entitled to be aware
of the circumstances surrounding the destruction and unavailability of
the drug evidence.

   The court then permitted Smith to voir dire Adams on the matter.
According to Adams (and the dismissal notice filed by the state prose-
cutor on November 7, 2003) the prosecution dismissed the state
charges because Smith was "facing a federal charge." J.A. 413.
Adams also testified that the evidence had been destroyed, nine
months after Smith was indicted by the federal grand jury, pursuant
to the police policy of destroying evidence involving cases which
have been voluntarily dismissed. Adams maintained, however, that he
had no knowledge of the federal indictment and that he did not order
the drugs destroyed to prevent Smith’s access to them.

   After considering the voir dire evidence of the officers, the district
court denied Smith’s motions to suppress. In so ruling, the court
determined that there was "no evidence of bad faith in terms of the
handling of the evidence or the execution of the policies" concerning
the evidence. S.J.A. 461. Significantly, the court also declined to per-
mit Smith to cross-examine the trial witnesses regarding the destroyed
drug evidence. By the court’s ruling, Smith was only permitted to
point out that the drug evidence had been destroyed and argue to the
jury that the absence of the evidence undermined the prosecution’s
claims that it was crack.

                                   b.

   We review for abuse of discretion a trial court’s limitations on a
defendant’s cross-examination of a prosecution witness. See United
States v. Scheetz, 293 F.3d 175, 184 (4th Cir. 2002). And we review
for clear error findings of fact made in connection with suppression
motions. See United States v. Wardrick, 350 F.3d 446, 451 (4th Cir.
2003). In circumstances where law enforcement officers have failed
14                      UNITED STATES v. SMITH
"to preserve evidentiary material of which no more can be said than
that it could have been subjected to tests, the results of which might
have exonerated the defendant," a defendant seeking to suppress testi-
monial evidence must show bad faith on the part of the officers to
establish a denial of his due process rights. See Arizona v. Young-
blood, 488 U.S. 51, 57 (1988); Lovitt v. True, 403 F.3d 171, 187 (4th
Cir. 2005). As the court found here, Smith was unable to show that
the drug evidence from the 1995 and 2000 Arrests was destroyed in
bad faith.

   In these circumstances, however, the trial court abused its discre-
tion in limiting Smith’s cross-examination of the witnesses regarding
destruction of the drug evidence seized during Smith’s 1995 and 2000
Arrests. As we have repeatedly observed, the right of "cross examina-
tion is a precious one, essential to a fair trial." United States v. Cole,
622 F.2d 98, 100 (4th Cir. 1980); see also United States v. McMillon,
14 F.3d 948, 956 (4th Cir. 1994) ("In a criminal context, cross-
examination is an important element of the right of confrontation.").
And although a trial court necessarily possesses wide latitude to
impose reasonable limits on cross-examination, premised on such
concerns as prejudice, confusion, repetition, and relevance, see, e.g.,
Fed. R. Evid. 403, its exercise of such discretion is limited by the
Constitution and the applicable rules of evidence. See Delaware v.
Van Arsdall, 475 U.S. 673, 679 (1986); United States v. Turner, 198
F.3d 425, 429 (4th Cir. 1999). Both the Fifth and the Sixth Amend-
ments guarantee an accused "a meaningful opportunity to present a
complete defense." United States v. Scheffer, 523 U.S. 303, 329
(1998) (internal quotation marks omitted). Indeed, the Supreme Court
has consistently recognized that a trial court should accord a criminal
defendant a reasonable opportunity to conduct cross-examination that
might undermine a witness’s testimony. See Olden v. Kentucky, 488
U.S. 227, 233 (1988) (per curiam); Van Arsdall, 475 U.S. at 679;
United States v. Abel, 469 U.S. 45, 52 (1984); Davis v. Alaska, 415
U.S. 308, 316-17 (1974). And the rules of evidence authorize the
cross-examination of witnesses on matters affecting their "credibil-
ity." See Fed. R. Evid. 607; see also Fed. R. Evid. 611(b) ("Cross-
examination should be limited to the subject matter of the direct pre-
sentation and matters affecting the credibility of the witness."). And,
the availability of appropriate cross-examination by an accused is
even more essential when the physical evidence, about which the wit-
                        UNITED STATES v. SMITH                       15
nesses are testifying, no longer exists. See United States v. Newsome,
322 F.3d 328, 334 (4th Cir. 2003) (recognizing that ability to cross
examine government witnesses on destroyed evidence with exculpa-
tory value lessens potential constitutional prejudice to defendant);
United States v. Belden, 957 F.2d 671, 674 (9th Cir. 1992) (observing
that prejudice to defendant due to law officers’ destruction of eviden-
tiary marijuana plants was mitigated by ability to cross-examine offi-
cers).

   In limiting Smith’s cross-examination of the prosecution witnesses
about the 1995 and 2000 seizures, the trial court concluded that any
relevance of the cross-examination Smith sought was "extremely
slight." J.A. 290-91. In fact, however, the examination Smith sought
to conduct was highly relevant to the issues in the case, in that the
prosecution witnesses were testifying that the substances were contra-
band and had been seized from Smith. The trustworthiness and com-
petence of these witnesses related directly to the charges in the
indictment, and their credibility was crucial to the jury’s assessment
of the prosecution’s case. See United States v. Turner, 198 F.3d 425,
429 n.2 (4th Cir. 1999) ("The partiality of a witness is always relevant
as discrediting the witness and affecting the weight of his testi-
mony.").

   Importantly, Adams’s testimony regarding the destruction of the
drug evidence seized during Smith’s 2000 Arrest raised obvious con-
cerns. Adams testified — and the November 7, 2003 notice of dis-
missal in state court indicates — that the state charges were dismissed
on account of federal charges which had been pending for nearly nine
months. Despite the pending federal charges, the evidence seized in
Hickory in 2000 was destroyed, assertedly under a police policy of
destroying evidence in cases which have been voluntarily dismissed.
To be sure, Adams testified that he was unaware of the pending fed-
eral charges when the evidence was destroyed. But given that the state
charges were dismissed precisely because of the pending federal
charges, cross-examination of Adams on this point would have cut to
the core of his credibility and was highly relevant to the issues before
the jury. And any resulting prejudice to the prosecution from a thor-
ough examination on the facts surrounding the evidence’s destruction
was plainly outweighed by Smith’s right to inquire into the pertinent
circumstances. The district court’s contrary conclusion — that the rel-
16                      UNITED STATES v. SMITH
evance of such cross-examination would have been "extremely slight"
— was thus based on a "clearly erroneous assessment of the evi-
dence," and constitutes an abuse of discretion. Cooter & Gell v. Hart-
marx Corp., 496 U.S. 384, 405 (1990).

                                   c.

   In these circumstances, however, the trial court’s erroneous restric-
tions on Smith’s cross-examination of the prosecution witnesses was
harmless. See Fed. R. Crim. P. 52(a) ("Any error, defect, irregularity,
or variance [in a criminal proceeding] that does not affect substantial
rights must be disregarded."). Whether an erroneous evidentiary rul-
ing is harmless in a particular case rests upon an analysis of a host
of factors, including:

     the importance of the witness’s testimony in the prosecu-
     tion’s case; whether the testimony was cumulative; the pres-
     ence or absence of evidence corroborating or contradicting
     the testimony of the witness on material points; the extent
     to which cross-examination was otherwise permitted; and,
     of course, the overall strength of the prosecution’s case.

Van Arsdell, 475 U.S. at 684. Here, the overall strength of the prose-
cution’s case was undeniable: There was ample evidence — from
multiple witnesses — that Smith was actively involved in the illegal
drug business in The Hill neighborhood of Hickory, buying and sell-
ing drugs with his co-conspirators during the period of the Count One
conspiracy. In addition, the evidence of his drug activity was corrobo-
rated by law officers who, in 1995, 2000, and 2001, had seized crack,
cocaine and large amounts of cash from Smith. Importantly, the 3.6
grams of crack and 1.5 grams of powder cocaine seized from Smith
in October 2001 (by the Newton police) had not been destroyed, and
that evidence presumably could have been tested by Smith had he
challenged its veracity. Given the strength of the prosecution’s case,
the court’s error in limiting Smith’s cross-examination on the
destroyed evidence issue was harmless. Consequently, Smith is not
entitled to a new trial.

                                   4.

  Smith next maintains the trial court improperly permitted several
witnesses to testify without sufficient personal knowledge of the mat-
                        UNITED STATES v. SMITH                        17
ters to which they testified. See Fed. R. Evid. 602 ("A witness may
not testify to a matter unless evidence is introduced sufficient to sup-
port a finding that the witness has personal knowledge of the mat-
ter.").

   Smith contends that it was error to permit Officer Adams of the
Hickory police to testify that "a lot of the residents" in the Hickory
public housing project sell crack to supplement their incomes. J.A.
167. Smith asserts that Adams lacked any personal knowledge to sup-
port this testimony. Officer Adams testified, however, that he was
familiar with drug dealing in the neighborhood of the housing project,
and the court was thus entitled to conclude he had sufficient personal
knowledge to so testify. And, as the prosecution observes, even if the
court erred in admitting this evidence, Adams’s testimony on this
point, assessed in light of the other evidence of Smith’s participation
in the Count One conspiracy, was relatively insignificant.

   Smith also asserts that it was erroneous to permit Squarles and All-
red to testify concerning Smith’s reputation for drug dealing. How-
ever, both Squarles and Allred had sufficient personal knowledge to
support their testimony — they each testified to having participated
personally in drug deals with Smith, and any error in permitting them
to testify to more general knowledge was also harmless. The district
court thus did not abuse its discretion in declining to grant a new trial
on this basis.

                                   5.

   Finally, Smith maintains that the district court erroneously
deprived him of his Sixth Amendment right of confrontation when it
refused to permit him to fully cross-examine prosecution witness Jer-
maine Anthony concerning Anthony’s alleged participation in an
unrelated shooting. At trial, Anthony testified that he was not present
at the alleged shooting, and there was no evidence presented to sug-
gest otherwise. When the prosecution asserted that the cross-
examination of Anthony being sought by Smith would not be rele-
vant, the court sustained the objection. In so ruling, the court observed
that such evidence would likely be hearsay because Anthony had
already testified he was not there.
18                      UNITED STATES v. SMITH
   Although the rules of evidence permit cross-examination of a wit-
ness about specific instances of misconduct if probative of truthful-
ness, the trial court has wide discretion to decide whether (and to
what extent) such questioning is proper and relevant. See Fed. R.
Evid. 608 ("Specific instances of the conduct of a witness [may] in
the discretion of the court, if probative of truthfulness or untruthful-
ness, be inquired into on cross-examination of the witness."). In these
circumstances, the trial court did not abuse its discretion in denying
Smith a new trial on this basis. See Hafner v. Brown, 983 F.2d 570,
576 (4th Cir. 1992) (observing that limitation on impeachment not
abuse of discretion given "dubious value" of questioning).

                                  C.

   Finally, Smith makes two appellate challenges to the sentences
imposed on him by the district court. First, he maintains that 21
U.S.C. § 851, to the extent that it permits a sentencing court to find
prior convictions and use them to enhance a defendant’s sentence, is
unconstitutional under United States v. Booker, 543 U.S. 220 (2005).
Second, he asserts that the sentencing court misapplied § 851 in this
case, because the prosecution failed to prove that Smith’s 1996 and
1997 state court convictions were in fact "prior" to the Count One
conspiracy. Both of these contentions must be rejected.

   Section 851 sets forth procedures to be followed in determining a
defendant’s prior convictions for sentencing purposes. It requires the
prosecutor to notify the defendant and the court, prior to trial or the
entry of a guilty plea, of any prior convictions on which the prosecu-
tor intends to rely. See § 851(a). A defendant who denies the convic-
tions must file a written response and is entitled to a hearing on the
matter. See § 851(c). If the court determines that the defendant has the
prior convictions alleged by the prosecution, it must enhance the
defendant’s sentence accordingly. See § 851(d)(1). Smith’s constitu-
tional challenge centers on the court’s role in finding a defendant’s
prior convictions and enhancing his sentence on that basis.

   As a general matter, a sentencing court, in finding facts that
increase a defendant’s sentence beyond the maximum authorized by
the facts admitted by the defendant or found by a jury, contravenes
the defendant’s Sixth Amendment right to trial by jury. See Booker,
                        UNITED STATES v. SMITH                        19
543 U.S. at 235. The sole exception to this rule is that a sentencing
court may, consistent with the Sixth Amendment, find "the fact of a
prior conviction" and use it to enhance a defendant’s sentence beyond
that otherwise authorized. Apprendi v. New Jersey, 530 U.S. 466, 490
(2000); see also Booker, 543 U.S. at 244 (reaffirming the prior con-
viction exception); Almendarez-Torres v. United States, 523 U.S. 224,
247 (1998) (holding that prior convictions need not be "treated as an
element of [an] offense"). Because § 851 permits judicial factfinding
on a defendant’s prior convictions, it falls within the prior conviction
exception.

   To be sure, the Sixth Amendment imposes limitations on how a
sentencing court may find facts relating to a prior conviction. As we
have recognized, in finding such facts, a sentencing court may only
look to "‘the terms of the charging document, the terms of a plea
agreement or transcript of colloquy between judge and defendant in
which the factual basis for the plea was confirmed by the defendant,
or . . . some comparable judicial record.’" See United States v. Allen,
446 F.3d 522, 531 (4th Cir. 2006) (quoting Shepard v. United States,
125 S. Ct. 1254, 1263 (2005)). Smith does not contend, however, that
the sentencing court looked outside the approved sources in finding
his prior convictions; rather, he mounts a broad attack on all judicial
factfinding required by § 851. Because the Sixth Amendment permits
a sentencing court, within the confines outlined in Shepard, to find
facts relating to a prior conviction, Smith’s constitutional challenge to
§ 851 is without merit.

   On his second sentencing point, Smith asserts that, because the jury
did not determine when the Count One conspiracy began or when it
ended, the sentencing court was unable to determine that his 1996 and
1997 convictions — which formed the basis for the § 851 enhance-
ment — were, in fact, "prior" convictions which could be used to
enhance his sentence. This contention is also without merit. The
indictment alleged that the Count One conspiracy began in January
1995 and continued until the indictment was returned on February 25,
2003. Thus, by its verdict finding Smith guilty on Count One, the jury
found that the charged conspiracy began in January 1995 and ended
in February 2003. Thus, Smith’s 1996 and 1997 convictions occurred
within the conspiracy period.
20                     UNITED STATES v. SMITH
   When a defendant is convicted of a drug conspiracy under 21
U.S.C. § 846, prior felony drug convictions that fall within the con-
spiracy period may be used to enhance the defendant’s sentence if the
conspiracy continued after his earlier convictions were final. See 21
U.S.C. § 841(b)(1)(A) (providing penalties for violations of § 846 and
stating that prior felony drug conviction may be used to enhance sen-
tence if it is final); see also United States v. Howard, 115 F.3d 1151,
1158 (4th Cir. 1997). Because the conspiracy for which Smith was
convicted continued well after his 1996 and 1997 convictions became
final, those convictions were properly considered prior convictions
for purposes of enhancing his sentence.

                                 IV.

  Pursuant to the foregoing, we reject Smith’s contentions of error
and affirm his convictions and sentence.

                                                          AFFIRMED
