                                                Filed:    June 14, 2007

                   UNITED STATES COURT OF APPEALS

                       FOR THE FOURTH CIRCUIT


                            No. 05-4435(L)
                             (CR-03-309-G)


UNITED STATES OF AMERICA,

                                                Plaintiff - Appellee,

          versus

GREGORY LAMONT WILSON, a/k/a Nice

                                               Defendant - Appellant.


                              O R D E R



     Upon consideration of counsel for appellant Powell’s request

for modification of the Court’s opinion, the court amends its

opinion filed April 19, 2007, as follows:

     On page 2, counsel information, line 8 -- the parenthetical

“(appointed on appeal)” is inserted after “Washington, D.C.”

                                     For the Court

                                          /s/ Patricia S. Connor

                                                  Clerk
                           PUBLISHED

UNITED STATES COURT OF APPEALS
                FOR THE FOURTH CIRCUIT


UNITED STATES OF AMERICA,              
                 Plaintiff-Appellee,
                 v.
                                                No. 05-4435
GREGORY LAMONT WILSON, a/k/a
Nice,
             Defendant-Appellant.
                                       
UNITED STATES OF AMERICA,              
                 Plaintiff-Appellee,
                 v.                             No. 05-4503
EDWIN LLOYD MURRAY, a/k/a Gator,
             Defendant-Appellant.
                                       
UNITED STATES OF AMERICA,              
                 Plaintiff-Appellee,
                 v.                             No. 05-4837
DERRICK LENWOOD POWELL,
             Defendant-Appellant.
                                       
          Appeals from the United States District Court
           for the District of Maryland, at Baltimore.
            Marvin J. Garbis, Senior District Judge.
                          (CR-03-309-G)

                      Argued: February 2, 2007

                      Decided: April 19, 2007
2                      UNITED STATES v. WILSON
Before NIEMEYER, WILLIAMS, and GREGORY, Circuit Judges.




Affirmed by published opinion. Judge Williams wrote the opinion, in
which Judge Niemeyer and Judge Gregory joined.


                             COUNSEL

ARGUED: Ann N. Sagerson, WILLIAMS & CONNOLLY, Washing-
ton, D.C., for Appellants. Martin Joseph Clarke, Assistant United States
Attorney, OFFICE OF THE UNITED STATES ATTORNEY,
Baltimore, Maryland, for Appellee. ON BRIEF: Thomas J. Saunders,
Baltimore, Maryland, for Appellant Gregory Lamont Wilson; Peter
Dennis Ward, Baltimore, Maryland, for Appellant Edwin Lloyd Mur-
ray; Philip A. Sechler, Amer S. Ahmed, WILLIAMS & CONNOLLY,
Washington, D.C. (appointed on appeal), for Appellant Derrick Len-
wood Powell. Rod J. Rosenstein, United States Attorney, Baltimore,
Maryland, for Appellee.


                              OPINION

WILLIAMS, Circuit Judge:

   Gregory Lamont Wilson, Edwin Lloyd Murray, and Derrick Len-
wood Powell appeal their convictions for conspiracy to distribute 5 or
more kilograms of cocaine and 50 grams or more of cocaine base, in vi-
olation of 21 U.S.C.A. § 841(a) (West 1999 & Supp. 2006). Wilson also
appeals his convictions under 18 U.S.C.A. § 924(c)(1)(A) (West 2000
& Supp. 2006) and 18 U.S.C.A. § 922(g)(1) (West 2000) for unlawfully
possessing a firearm on September 14, 2002. Finding no reversible error,
we affirm.

                                   I.

  On September 13, 2002, Baltimore County Police officers stopped
a vehicle driven by Dieter Munz, a known drug dealer, for a minor
                      UNITED STATES v. WILSON                       3
traffic offense. Upon searching Munz’s vehicle, the officers found
and seized plastic baggies containing crack cocaine and marijuana.
Based on other evidence found in the vehicle that linked Munz’s resi-
dence at the time to 8832 Tamar Drive, Apartment 302, in Howard
County, Maryland (Tamar Drive apartment), officers obtained a
search warrant and executed it at that location the following day.

   At the Tamar Drive apartment, the police found various items that
indicated that the occupants of the house were involved in the drug
trade. In the master bedroom, the police discovered what they
believed to be a "drug owe sheet," which is sometimes used by drug
distributers to keep track of the amount of drugs that have been pro-
vided to customers on consignment. The "drug owe sheet" was in an
envelope addressed to Appellant Wilson’s girlfriend. Also in the mas-
ter bedroom, the police discovered a loaded .45 caliber pistol, paper-
work in Munz’s name, a traffic violation in Wilson’s name, a prisoner
property inventory in Wilson’s name, and a package of photographs
with Appellant Powell’s name on the front, as well as $3000 in cash.
In the second bedroom, police recovered paperwork in Appellant
Murray’s name, ammunition, and over $11,000 in cash.

  Four days after the search, while conducting surveillance of the
Tamar Drive apartment, the police observed Wilson and Murray
removing furniture from the building. When the detectives entered the
apartment, they found a jacket with $2500 in the pocket, which Wil-
son claimed belonged to him.

   The police began to monitor Wilson’s movements, and on January
7, 2003, officers followed Wilson and Michael White to a gas station.
At the gas station, they observed Wilson take money from an individ-
ual; White then handed the individual a white object slightly larger
than the size of a golf ball. Because police had observed Wilson and
White going in and out of an apartment on Wheatley Drive in Balti-
more County (Wheatley Drive apartment), they executed a search
warrant at that location shortly thereafter. When police searched the
apartment, Wilson, White, and another individual were present, but
the apartment was barely furnished. In one bedroom, police discov-
ered a digital scale with cocaine residue, $1900 in currency, and
paperwork in Wilson’s name. In a second bedroom, police discovered
paperwork in White’s name, a loaded .44 caliber handgun, and
4                      UNITED STATES v. WILSON
another digital scale with cocaine residue. In the kitchen, the police
found pots and pans with crack cocaine residue and more paperwork
in Wilson’s name.

   Around the time of the Wheatley Drive apartment search, Balti-
more County police began using a confidential informant to make
controlled cocaine purchases from Anderson Hicks, an indicted
coconspirator who ultimately pleaded guilty and testified at trial
against Appellants. By following Hicks, police learned that his supply
source was at an apartment building at 4402 Old Court Road,
Randallstown, Maryland. On one occasion, Hicks was seen driving
there in a vehicle owned by Derrick Powell. On January 24, 2003,
police set up surveillance inside an apartment unit in the building.
After instructing an informant to order crack cocaine from Hicks,
police observed Hicks entering Apartment A (Old Court Road apart-
ment), the same apartment that Wilson had entered earlier. At approx-
imately the same time, a man was observed leaving the apartment and
going to his vehicle. This man is believed to have been Powell.
Shortly thereafter, the police began their raid to arrest Hicks and his
supplier. Upon seeing the formations of the raid, Powell used his cell
phone to warn the coconspirators in the apartment.

   When the police entered the building, they heard people running
from Apartment A. Wilson and Hicks had fled the apartment and
forced their way into Apartment F, where Hicks was arrested. Wilson
was arrested after he jumped from the balcony. Murray was found in
Apartment A and arrested. In Apartment A, the police found approxi-
mately 186 grams of crack cocaine, 248 grams of powder cocaine, a
digital scale, sandwich bags, pots, a spoon, and a knife, all containing
drug residue. Police also discovered two handguns.

   Shortly thereafter, in February 2003, Baltimore County police
joined with federal task force officers in an effort to investigate the
Wilson organization. On April 17, 2003, the investigators applied for
and received authorization to wiretap cellular telephones used by Wil-
son, Murray, and others. These recorded conversations would become
a central facet of the Government’s case at trial.

  On July 3, 2003, Wilson, Murray, Powell, and other coconspirators
were indicted in the District of Maryland and charged with conspiracy
                       UNITED STATES v. WILSON                        5
to distribute 5 or more kilograms of cocaine and 50 grams or more
of cocaine base, in violation of 21 U.S.C. § 841(a)(1). Wilson was
also charged with three counts of possession of a firearm in further-
ance of a drug trafficking crime, and Murray with one count, in viola-
tion of 18 U.S.C. § 924(c)(1). In addition, Wilson was charged with
being a felon in possession of a firearm, in violation of 18 U.S.C.
§ 924(g)(1). Finally, both Wilson and Murray were charged with pos-
session with intent to distribute cocaine and cocaine base, in violation
of 21 U.S.C. § 841(a)(1).

   On January 20, 2004, the trial began with jury selection; the trial
spanned 33 days and ended on February 23, 2004. At trial, the Gov-
ernment’s case-in-chief relied on numerous witnesses, including
coconspirators who had agreed to cooperate as well as Government
investigators. A brief summary of the testimony most pertinent to this
appeal is provided below.

   One of the Government’s key witnesses was Anderson Hicks, the
same man who led police to the stash apartment on Old Court Road.
Hicks, who was testifying pursuant to a state plea agreement, stated
that Murray had supplied him with cocaine and crack cocaine. Hicks
testified that in February, 2002, he picked up crack cocaine from one
of the apartments in the complex on Old Court Road. When Hicks
arrived, Wilson, Powell, and Murray were all present. Hicks was told
that the apartment belonged to Powell, while Murray and Wilson
lived together at the Tamar Drive apartment. Hicks returned to the
Old Court Road apartment every few weeks to resupply. On one occa-
sion later that year, Murray told Hicks that he was too busy to sell to
him so that Hicks should go to Wilson instead.

   Hicks was arrested in July 2002. After his arrest, Murray and Wil-
son warned him to cease dealing for a while because the police would
be looking at him closely. Regardless, Powell agreed to "take care"
of Hicks by supplying him with crack cocaine on multiple occasions.
(J.A. at 431.)1 Thus, until his arrest at the Randallstown apartment on
January 24, 2003, Hicks testified that he was supplied by Murray,
Wilson, and Powell.
  1
   Citations to the "J.A." refer to the joint appendix filed with this
appeal.
6                      UNITED STATES v. WILSON
   Andre Clark also testified. Clark was a supplier to the conspiracy,
and testified that he usually delivered an eighth or quarter kilogram
of cocaine to Wilson and watched Wilson convert it into crack
cocaine. Clark was eventually arrested while returning to Maryland
from Georgia with a kilogram of cocaine, nine ounces of which was
to be given to Wilson. The Government also called Mark Halley, who
indicated that he supplied both Wilson and Murray with cocaine, and
that Powell was occasionally with the men during their dealings.

   The Government thereafter called Damon Thomas, who testified
pursuant to a federal plea agreement. Thomas stated that he supplied
fraudulent documents, such as pay stubs, employment verification let-
ters, automobile tags, and identification documents to coconspirators.
Thus, to make it appear that Wilson, Powell, and Murray were law-
fully employed, Thomas provided them with fake pay stubs that
allowed them to purchase vehicles and rent apartments. Thomas had
also lived in one of the apartments at the complex on Old Court Road.

   Finally, the Government called various law enforcement officers,
including Detective Seabolt, who provided more testimony than any
other Government witness. Seabolt testified about his role in the
investigation of the conspiracy. Furthermore, he was called as an
expert to decipher the intercepted communications that were recorded
via wiretap. The communications were full of drug slang and street
code, and the district court allowed Seabolt to testify — over the
defense’s objection — as an expert as to the meanings of various
words used by the coconspirators. Seabolt was thus able to testify as
a fact witness, as well as present to the jury what he believed to be
the true meaning of various code words and slang used by Wilson,
Murray, Powell, and others.

   At the conclusion of the trial, the jury found the defendants guilty
of conspiracy to distribute cocaine and cocaine base, in violation of
21 U.S.C. § 841(a). Wilson was also found guilty of being in posses-
sion of a firearm in furtherance of a drug trafficking crime, being a
felon in possession of a firearm, and possession with intent to distrib-
ute 50 grams or more of crack cocaine. Murray was found guilty of
being in possession of a firearm in furtherance of a drug trafficking
crime and possession with intent to distribute 50 grams or more of
crack cocaine. Wilson was sentenced to 300 months’ imprisonment;
                       UNITED STATES v. WILSON                          7
Murray was also sentenced to 300 months’ imprisonment; Powell was
sentenced to 120 months’ imprisonment.

  Appellants timely appealed. We have jurisdiction pursuant to 28
U.S.C.A. § 1291 (West 2006).

                                   II.

   Wilson, Murray, and Powell make a number of arguments on
appeal. First, Appellants claim that the district court erred in allowing
Seabolt to testify as an expert witness. Second, they contend that the
district court erred in giving misleading jury instructions. Third,
Appellants argue that the district court erred in not suppressing the
wiretaps. Fourth, they contend that there was insufficient evidence to
support a conviction for conspiracy. Finally, Wilson argues there was
insufficient evidence to support his firearms convictions. We address
these arguments2 in turn.

                                   III.

  At trial, Appellants objected to the qualification of Seabolt as an
expert "in the field of investigating drug trafficking in the Baltimore
metropolitan region." (J.A. at 515.) On appeal, they contend that Sea-
bolt’s methodology for translating drug codes was neither sufficiently
explained nor reliable.

   We review for abuse of discretion the district court’s decision to
admit expert testimony under Federal Rule of Evidence 702. See, e.g.,
Kumho Tire Co. v. Carmichael, 526 U.S. 137, 152 (1999). A "trial
judge must have considerable leeway in deciding in a particular case
how to go about determining whether particular expert testimony is
reliable." Id. Thus, "Rule 702 grants the district judge the discretion-
ary authority, reviewable for its abuse, to determine reliability in light
of the particular facts and circumstances of the particular case." Id. at
158.
  2
   Wilson also made arguments challenging his sentence. At oral argu-
ment, counsel waived these arguments because they were not beneficial
to Wilson. We therefore do not address them.
8                       UNITED STATES v. WILSON
   The thrust of Appellants’ argument is that Seabolt failed to explain
adequately how his experience in the narcotics field supported the
methodology used and the ultimate conclusions made concerning the
coded language spoken in the recorded conversations. The Govern-
ment, on the other hand, contends that "Seabolt was a highly experi-
enced narcotics investigator who applied reasonable and reliable
methods to help jurors identify and understand patterns of drug-
related dialogue contained within seemingly convoluted and dis-
jointed conversations." (Appellee’s Br. at 14.)

  Federal Rule of Evidence 702 serves as our guidepost. The rule
provides:

     If scientific, technical, or other specialized knowledge will
     assist the trier of fact to understand the evidence or to deter-
     mine a fact in issue, a witness qualified as an expert by
     knowledge, skill, experience, training, or education, may
     testify thereto in the form of an opinion or otherwise, if (1)
     the testimony is based upon sufficient facts or data, (2) the
     testimony is the product of reliable principles and methods,
     and (3) the witness has applied the principles and methods
     reliably to the facts of the case.

The rule "requires that the [expert] testimony must be the product of
reliable principles and methods that are reliably applied to the facts
of the case." Fed. R. Evid. 702 advisory committee’s note. But, "the
test of reliability is flexible" and "the law grants a district court the
same broad latitude when it decides how to determine reliability as it
enjoys in respect to its ultimate reliability determination." Kumho Tire
Co., 526 U.S. at 141-42 (internal quotation marks omitted).

   We have little trouble concluding that the district court did not
abuse its discretion in qualifying Seabolt as an expert. A district
court’s reliability determination does not exist in a vacuum, as there
exist meaningful differences in how reliability must be examined with
respect to expert testimony that is primarily experiential in nature as
opposed to scientific. Purely scientific testimony, for example, is
characterized by "its falsifiability, or refutability, or testability." Dau-
bert v. Merrell Dow Pharms., Inc., 509 U.S. 579, 593 (1993) (quoting
K. Popper, Conjectures and Refutations: The Growth of Scientific
                       UNITED STATES v. WILSON                          9
Knowledge 37 (5th ed. 1989)). Thus, such evidence is "objectively
verifiable, and subject to the expectations of falsifiability, peer
review, and publication." Fed. R. Evid. 702 advisory committee’s
note.

   Experiential expert testimony, on the other hand, does not "rely on
anything like a scientific method." Id. But this does not lead to a con-
clusion that "experience alone — or experience in conjunction with
other knowledge, skill, training or education — may not provide a
sufficient foundation for expert testimony. To the contrary, the text of
Rule 702 expressly contemplates that an expert may be qualified on
the basis of experience." Id. While a district court’s task in examining
the reliability of experiential expert testimony is therefore somewhat
more opaque, the district court must nonetheless require an experien-
tial witness to "explain how [his] experience leads to the conclusion
reached, why [his] experience is a sufficient basis for the opinion, and
how [his] experience is reliably applied to the facts." Id.

   The advisory committee notes specifically consider testimony by a
law enforcement agent concerning the use of code words in drug
transactions:

    [T]he principle used by the agent is that participants in such
    transactions regularly use code words to conceal the nature
    of their activities. The method used by the agent is the appli-
    cation of extensive experience to analyze the meaning of the
    conversations. So long as the principles and methods are
    reliable and applied reliably to the facts of the case, this type
    of testimony should be admitted.

Id. (emphasis added). Unsurprisingly, then, courts of appeals have
routinely held that law enforcement officers with extensive drug
experience are qualified to give expert testimony on the meaning of
drug-related code words. See, e.g., United States v. Gibbs, 190 F.3d
188, 211 (3d Cir. 1999) ("[I]t is well established that experienced
government agents may testify to the meaning of coded drug language
under Fed. R. Evid. 702."); United States v. Griffith, 118 F.3d 318,
321-22 (5th Cir. 1997) (holding that experienced narcotics officers
may offer expert testimony with respect to "drug traffickers’ jargon");
United States v. Delpit, 94 F.3d 1134, 1145 (8th Cir. 1996) (holding
10                     UNITED STATES v. WILSON
that an experienced officer was qualified to give expert testimony
concerning the "meaning of jargon and codewords" because his expe-
rience represented "the best education there is for this type of thing");
see also United States v. Garcia, 291 F.3d 127, 139 (2d Cir. 2002)
("Given the attempts of drug dealers to disguise the content of their
discussions as legitimate subject matters, courts may allow witnesses
to ‘decipher’ the codes drug dealers use and testify to the true mean-
ing of the conversations.").

   Before the district court, Seabolt summarized his methodology. He
began by explaining that his experience and training in investigating
narcotics trafficking confirmed that drug dealers often use coded
words and phrases in describing their business. He then explained that
he listened to intercepted conversations to see if they contained words
that appeared to have dual meanings, as in, for example, a dictionary
meaning and a drug meaning. By listening to a number of drug-
related conversations in context, he was able to sometimes identify a
word pattern that led him to decipher the code. Accordingly, Seabolt
stated: "I . . . take everything that I have, my knowledge, the situation,
and that’s how I form my opinion." (J.A. at 518.) More specifically,
he explained:

     It all depends on the situation. I mean, there’s, obviously,
     there’s a lot of words to mean one thing. So like I say, you
     take it into the context of what you’re talking about. That’s
     how you determine. . . . It all depends on the context of the
     call. You know, drug dealers use coded language. And the
     reason that they do that is because they don’t want police
     involvement or police to know what they’re talking about.
     . . . I take the person who’s talking, the conversation. I take
     what has this person, what’s the routine pattern of this per-
     son before and the pattern after. And that’s how I make my
     determination. . . . [W]hen you hear [a] word time and time
     again . . . then there’s a pattern that develops. And when that
     pattern develops, that ultimately shows you what they’re
     talking about.

(J.A. at 518-519.)

  Seabolt was a nine-year veteran of the Baltimore County Police
Department. He spent most of his career investigating narcotics traf-
                        UNITED STATES v. WILSON                         11
fickers and had participated in hundreds of drug investigations and
arrests. At the time of his testimony, he was a detective in the Central
Narcotics Unit in Baltimore County. Seabolt had attended seminars
and classes offered by the U.S. Drug Enforcement Administration
(DEA), and part of his course training dealt with coded language. He
was sworn in as a federal task force officer with the DEA. He stated
that in the course of his extensive experience dealing with drug traf-
fickers and confidential informants, he was able to learn to understand
the vernacular used by drug traffickers.

    Seabolt’s extensive "experience" qualified him to testify as an
expert based on his "specialized knowledge" of drug traffickers’
coded vernacular. Fed. R. Evid. 702. "Because the primary purpose
of coded drug language is to conceal the meaning of the conversation
from outsiders through deliberate obscurity, drug traffickers’ jargon
is a specialized body of knowledge and thus an appropriate subject for
expert testimony." Gibbs, 190 F.3d at 211; see also Griffith, 118 F.3d
at 321 ("Drug traffickers’ jargon is a specialized body of knowledge
. . . ."); United States v. Walls, 70 F.3d 1323, 1326 (D.C. Cir. 1995)
(holding that law enforcement agents’ specialized knowledge of drug
jargon would assist the jury’s understanding of the evidence). Further-
more, Seabolt’s general method and principles in applying his experi-
ence and specialized knowledge to decipher the conspiracy’s drug
vernacular were sufficiently reliable.3
  3
    Appellants urge us to follow the Ninth Circuit’s reasoning in United
States v. Hermanek, 289 F.3d 1076 (9th Cir. 2002), where the court held
that an officer’s interpretations were inadmissible because the interpreta-
tions were based on his belief of the defendant’s guilt. Hermanek is inap-
posite to this case. The Ninth Circuit’s holding was anchored by the
officer’s description of his methodology, which stated that he "inter-
preted such [code] words based on his knowledge of the defendants." Id.
at 1096. Seabolt’s methodology was meaningfully different, as he relied
primarily on his experience in looking to the context of the jargon used
in relation to the language surrounding the jargon and the speaker’s use
of such language in the past and future, as opposed to starting with an
assumption that any uncertain word must be referring to drugs because
he was listening to the conversations of drug dealers. Moreover, the
Ninth Circuit recently explained that Hermanek does not stand for the
broad proposition urged by Appellants. In United States v. Decoud, 456
F.3d 996 (9th Cir. 2006), the court held that the Government satisfied
Hermanek when it set "forth the expert’s experience" and explained "the
expert’s methodology for interpreting new encoded words." Id. at 1013-
14.
12                     UNITED STATES v. WILSON
   This is not to say, however, that Seabolt’s method and principles
were always applied reliably to the facts of the case throughout the
course of his expert testimony. See Fed. R. Evid. 702 advisory com-
mittee note ("So long as the principles and methods are reliable and
applied reliably to the facts of the case, this type of testimony should
be admitted." (emphasis added)). Because Appellants did not object
to any specific instances where they believed Seabolt did not follow
his stated methodology, we review for plain error their claims that
some of Seabolt’s specific testimony was erroneously admitted.

   After allowing Seabolt to testify as an expert, the district court was
careful to note that when Seabolt opined on the true meaning of a
coded word, he would, of course, be required "to explain" the basis
for his opinion. (J.A. at 524.) Nevertheless, over the course of Sea-
bolt’s testimony, there were instances where Seabolt offered his inter-
pretation of the meaning of a conversation without offering any
reliable explanation as to why he opined that the conversation meant
what it did.

   For example, after playing a recording in which Murray stated, "he
take too long, I’m going to go see my other man, yo," (J.A. at 1725),
Seabolt stated that he understood that expression to mean that if he
"keeps on taking forever to supply him, that he’s going to go to
another supplier." (J.A. at 680.) This type of testimony, however, was
unhelpful to the jury. See United States v. Dicker, 853 F.2d 1102,
1108 (3d Cir. 1988) ("Although courts have construed the helpfulness
requirement of Fed. R. Evid. 701 and 702 to allow the interpretation
by a witness of coded or ‘code-like’ conversations, they have held
that the interpretation of clear conversations is not helpful to the jury,
and thus is not admissible under either rule."). Seabolt was not so
much interpreting the meaning of Murray’s quoted language as he
was adding language to it. The actual language used by Murray
needed no translation; Murray was explaining that because someone
was taking too long, Murray may be forced to go elsewhere.

   It may have been the case that Murray’s next sentence — "I’m try-
ing to wait on him, cause I don’t want him to get the shit and then
don’t get it" (J.A. at 1725) — made it clear to Seabolt that Murray
was using the code "shit" to refer to drugs and that the word "man"
referred to a supplier. But the Government never asked Seabolt about
                       UNITED STATES v. WILSON                        13
the next sentence and he never explained its meaning, and without
some further explanation about the importance of the context pro-
vided by that next sentence, Seabolt’s translation of "man" to "sup-
plier" was unreliable.

   Although there are other instances in the record where Seabolt did
not adequately explain the application of his methodology to a spe-
cific translation, it is clear that he applied his methods and principles
reliably in the vast majority of his testimony. Consider, for example,
a portion of a conversation recorded between Wilson and White:

    White: You already get into the um, get your shop back
    on.

    Wilson: Na, I don’t . . . I don’t even got no way to get into
    the kitchen at.

    White: Oh all right.

    Wilson: Hold on yo . . . What you on easy? You on easy
    hah.

    White: Hah?

    Wilson: You on easy hah . . .

    White: Yeah, . . . I just gave Kenneth another two hundred
    dollars, so I need to get good.

    Wilson: All right I got some change, like, I think it’s like
    two, two of them, two, like two out of a ball, you know what
    I mean?

(J.A. at 1693.)

  When questioned about this conversation, Seabolt explained that he
believed that White was asking Wilson if he had a supply of drugs
when he asked about getting his "shop back on." Seabolt then
explained that "kitchen" is a word that would be heard in other con-
14                       UNITED STATES v. WILSON
versations, and that it referred to a place where powder cocaine would
be converted into crack cocaine. A brief discussion ensued concerning
the need of a heat source to convert powder cocaine into crack
cocaine. The Government then asked Seabolt what the phrase "what
you on easy" meant. Seabolt responded, "Easy is a term used, you’ll
hear that again, as meaning that you’re out of drugs." (J.A. at 637.)
Seabolt likewise explained that the phrase "get good" would be heard
again, and that it meant that White needed resupplying. Seabolt then
explained that he was uncertain over the meaning of the phrase "an-
other $200" and could not say that it was drug related. He also
explained that although "a ball" referred to an eight ball, or 3.5 grams
of cocaine, he could not say what specific amount was being dis-
cussed when Wilson stated he had some "change" or "like two out of
a ball."

    This example details how Seabolt’s methodology was reliably
applied in the vast majority of instances. In explaining his methodol-
ogy, Seabolt stated that "when you hear [a] word time and time again
. . . then there’s a pattern that develops. And when that pattern devel-
ops, that ultimately shows you what they’re talking about." (J.A. at
521.) When reviewing the recorded conversations, Seabolt repeatedly
heard the terms "kitchen," "on easy," and "get good." By studying the
context in which these phrases were used and the pattern of their use,
Seabolt was able to decipher the words’ meaning, as understood by
the coconspirators. But when he was unable to say whether a word or
phrase had a non-dictionary drug meaning, he candidly admitted as
much.

     So although the district court erred4 in failing to exclude Seabolt’s
  4
   We note that Appellants deserve some of the blame for those rare
instances where improper testimony slipped through the gate’s cracks.
See Gen. Elec. Co. v. Joiner, 522 U.S. 136, 142 (1999) (explaining that
the Federal Rules of Evidence require district courts to perform their
"gatekeeper" role in screening expert testimony). Appellants cite a num-
ber of instances in the record where they believe Seabolt offered unreli-
able testimony, but they did not offer any objections at trial to Seabolt’s
specific testimony.
   When evidence is erroneously admitted at trial, a party must file "a
timely objection or motion to strike . . . , stating the specific ground of
                         UNITED STATES v. WILSON                            15
testimony when that testimony either interpreted language that needed
no interpretation, or when Seabolt did not adequately explain his
methodology in reaching a questionable interpretation, the net effect
was harmless because the overwhelming majority of Seabolt’s expert
testimony was properly admitted, that properly admitted testimony
was alone sufficient to show Appellants’ guilt with respect to the con-
spiracy charges, and any prejudice that flowed from the limited
amount of improper testimony was outweighed by Seabolt’s properly
admitted expert testimony and the corroborative testimony of cocon-
spirators. We therefore conclude that even assuming that the district
court’s error was plain, the error did not affect Appellants’ substantial
rights. See, e.g., United States v. Olano, 507 U.S. 725, 732 (1993)
("There must be an ‘error’ that is ‘plain’ and that ‘affects substantial
rights.’" (internal alteration omitted)).5

objection, if the specific ground was not apparent from the context." Fed.
R. Evid. 103. Although Appellants objected to Seabolt’s qualifications
and to his methodology before he testified, the district court properly
overruled those objections. But once Seabolt began his expert testimony,
Appellants could have objected to specific instances where they felt his
testimony impermissibly skirted away from his stated methodology or
where it offered opinions that were not helpful to the jury. Beyond that,
they could have attacked Seabolt’s interpretations during cross examina-
tion.
   5
     Appellants also argue that the district court erred in allowing Seabolt
to testify as both a fact witness and an expert witness. Although we rec-
ognize that such dual witnesses could confuse the jury, see United States
v. Thomas, 74 F.3d 676, 682 (6th Cir. 1996) ("[W]hen a police officer
testifies in two different capacities in the same case, there is a significant
risk that the jury will be confused by the officer’s dual role."), the district
court took adequate steps — including having Seabolt testify first as a
fact witness and issuing a cautionary instruction to the jury — to make
certain that Seabolt’s dual role did not prejudice or confuse the jury. See
United States v. Parra, 402 F.3d 752, 760 (7th Cir. 2005) ("The potential
for prejudice in this circumstance can be addressed by means of appro-
priate cautionary instructions and by examination of the witness that is
structured in such a way as to make clear when the witness is testifying
to facts and when he is offering his opinion as an expert." (internal quo-
tation marks omitted)). The district court therefore did not abuse its dis-
cretion. See Fed. R. Evid. 701 advisory committee’s note ("The
amendment does not distinguish between expert and law witnesses, but
rather expert and lay testimony. Certainly it is possible for the same wit-
ness to provide both lay and expert testimony in a single case.").
16                     UNITED STATES v. WILSON
                                   IV.

   Appellants next contend that the district court committed prejudi-
cial error when delivering three of its jury instructions. First, they
argue that the district court erred by instructing the jury that it was
"the only jury that has ever decided or will decide whether the gov-
ernment’s carried its burden of proof." (J.A. at 1549.) Second, they
argue that the district court failed to instruct the jury on all the ele-
ments of a conspiracy charge insomuch as the court’s instructions pre-
sumed the existence of "an unlawful agreement." (J.A. at 1552.)
Third, they argue that the district court narrowed the Government’s
burden of proof by providing examples of a conspiracy that closely
resembled the facts of the case with respect to Powell.

   Because Appellants failed to object at trial, we review the district
court’s jury instructions for plain error. See United States v. Stitt, 250
F.3d 878, 883 (4th Cir. 2001). Under plain error review, Appellants
must show that (1) the district court committed error, (2) the error was
plain, and (3) the error affected their substantial rights. See, e.g.,
Olano, 507 U.,S. at 732. If Appellants satisfy this three-part showing,
"correction of the error nevertheless remains within our discretion,
which we should not exercise unless the error seriously affects the
fairness, integrity, or public reputation of judicial proceedings."
United States v. Hadden, 475 F.3d 652, 670 (4th Cir. 2007). We con-
clude that Appellants cannot satisfy the first prong of the test because
the district court did not err.

   As to Appellants’ first contention, they argue that by telling the
jury that it was the only jury that would ever decide the question, the
district court delivered something akin to an impermissible, i.e. coer-
cive, Allen charge.6 "[T]he principal concern that we have had with
Allen charges is to ensure that they apply pressure to the jury in a way
that preserves all jurors’ independent judgments and that they do so
in a balanced manner." United States v. Hylton, 349 F.3d 781, 788
(4th Cir. 2003).
  6
   The term "Allen charge" stems from the Supreme Court’s opinion in
Allen v. United States, 164 U.S. 492 (1896), where the district court
instructed the minority in a deadlocked jury to consider whether the
majority was correct.
                       UNITED STATES v. WILSON                          17
    When examining the entirety of the disputed instruction, however,
it is clear that the district court was not attempting to coerce the jury
into reaching a unanimous verdict, and no reasonable juror would
have felt pressured by the instruction:

     You will get the indictment. The indictment, it’s important
     to emphasize, is no evidence. It is the accusation. And you
     can look at it to see what the accusation is. That’s all it is.
     The government took the proper procedural steps to get
     here. This is the only trial there’s ever been. This is the only
     jury that has ever decided or will decide whether the govern-
     ment’s carried its burden of proof.

(J.A. at 1549.) Nothing in this charge urges — let alone coerces —
the jury toward unanimity, nor does the charge even address the pos-
sibility of a mistrial. Rather, it is simply an awkward attempt by the
district court to explain to the jury that as the jury, they alone must
decide whether the Government met its burden of proof.

  Appellants’ second contention involves the following instruction:

     Well, what does the government have to prove to establish
     guilt on [the conspiracy charges]? They must establish the
     following essential elements beyond a reasonable doubt.
     One is that at least two or more persons entered the unlawful
     agreement charged in the indictment. And two, that each
     defendant knowingly and willfully became a member of the
     conspiracy. Let me address those two points, and then
     there’s some other points that I will also mention.

(J.A. at 1552.) Appellants argue that this instruction "failed to instruct
the jury that they must determine beyond a reasonable doubt whether
an unlawful agreement existed at all." (Appellant’s Br. at 29.)

  Appellants’ argument, however, fails to view the instruction in
context. Courts have repeatedly held that jury instructions "may not
be judged in artificial isolation, but must be considered in the context
of the instructions as a whole and the trial record." Estelle v.
McGuire, 502 U.S. 62, 72 (1991) (internal quotation marks omitted);
18                     UNITED STATES v. WILSON
see United States v. Hsu, 364 F.3d 192, 204 (4th Cir. 2004) ("To
determine whether jury instructions require reversal, however, we
assess the instructions as a whole and view them in context.").

   Immediately after it gave the above instruction, the district court
explained to the jury that the Government had to prove beyond a rea-
sonable doubt that "two or more persons entered into the unlawful
agreement charged in the indictment." (J.A. at 1553.) The court there-
after instructed the jury what it may consider "in determining whether
an agreement existed here," and that it was the Government’s burden
to prove that there was a "mutual understanding" between two or
more people to accomplish an unlawful act. (J.A. at 1553 (emphasis
added).) Looking at the instructions in context, then, Appellants’
argument is without merit.

   Finally, Powell argues that the district court erred in instructing the
jury that participation in a conspiracy could be proven, in part, by
showing that an individual "alert[ed] coconspirators to the presence
of law enforcement agents in certain areas." (J.A. at 1556.) Powell
urges a novel claim that this instruction was error because it closely
resembled some of Powell’s alleged actions that were put forth at
trial. Powell cites no caselaw for this proposition, and it is without
merit. The court was careful to point out that mere presence or associ-
ation was insufficient to prove knowing participation in a conspiracy,
and the court continually reminded the jury that an individual’s partic-
ipation must be knowing and willful. Thus, just as it was not error for
the court to explain that the storing or selling of drugs in connection
with the conspiracy could prove participation, the challenged instruc-
tion was likewise not in error.

                                   V.

   Appellants next argue that the district court erred in not suppress-
ing evidence obtained from the wiretaps. They contend that the wire-
taps were not necessary under 18 U.S.C.A. § 2518(3) (West 2000)
because the Government had previously been highly successful in its
use of normal investigative procedures.

  We review for clear error the factual findings underlying a district
court’s ruling on a motion to suppress, and we review the court’s
                       UNITED STATES v. WILSON                        19
legal conclusions de novo. See, e.g., Ornelas v. United States, 517
U.S. 690, 699 (1996). We previously have declined to specify a stan-
dard of review when confronted with an authorizing court’s determi-
nation of necessity under § 2518(3). See United States v. Smith, 31
F.3d 1294, 1298 (4th Cir. 1994) (declining to identify the appropriate
standard of review). We now hold that we review for abuse of discre-
tion determinations of necessity under § 2518. See United States v.
Bennett, 219 F.3d 1117, 1121 (5th Cir. 2000) ("We review for abuse
of discretion an issuing judge’s decision that a wiretap was neces-
sary."); United States v. Corrado, 227 F.3d 528, 539 (6th Cir. 2000)
(same); United States v. Phillips, 959 F.2d 1187, 1190 (3d Cir. 1992)
(same); United States v. Sobamowo, 892 F.2d 90, 93 (D.C. Cir. 1989)
(same); United States v. Brown, 761 F.2d 1272, 1275 (9th Cir. 1985)
(same). But see United States v. Vanmeter, 278 F.3d 1156, 1163 (10th
Cir. 2002) (de novo review); United States v. Green, 40 F.3d 1167,
1172-73 (11th Cir. 1994) (clear error review); United States v. Davis,
882 F.2d 1134, 1343 (8th Cir. 1989) (same).

   Congress has placed a burden on the Government to show the "ne-
cessity" of any wiretap application via a full and complete statement
as to whether "normal investigative procedures have been tried and
have failed or reasonably appear to be unlikely to succeed if tried or
to be too dangerous." 18 U.S.C.A. § 2518(3). The burden that this
provision imposes on the Government, however, "is not great, and the
adequacy of such a showing is to be tested in a practical and com-
monsense fashion that does not hamper unduly the investigative pow-
ers of law enforcement agents." Smith, 31 F.3d at 1297 (internal
quotation marks and citation omitted). Although wiretaps are disfa-
vored tools of law enforcement, the Government "need only present
specific factual information sufficient to establish that it has encoun-
tered difficulties in penetrating the criminal enterprise or in gathering
evidence [such that] wiretapping becomes reasonable." Id. at 1298
(internal quotation marks, alteration, and citation omitted).

   The Government’s affidavits in support of the wiretap application
span 64 pages in the Joint Appendix. (J.A. at 76-139.) In exhaustive
fashion, they set forth the techniques that had been used up to that
point. Those techniques included confidential informants, undercover
agents, surveillance, trash searches, interviews, search warrants, tele-
phone records, reverse buys, GPS trackers, and financial and public
20                     UNITED STATES v. WILSON
records. The affiants then explained that despite the information they
had been able to gain from these traditional sources, they believed
that those sources, standing alone, were insufficient to achieve the
goals of the investigation and prove the extent of the conspiracy. For
example, they explained that confidential informants were unable to
identify the higher-ups of the conspiracy. See United States v. Leavis,
853 F.2d 215, 221 (4th Cir. 1988) (holding that a wiretap may be nec-
essary when an "informant would be unable to provide information
regarding the upper levels of the conspiracy"). The traditional sources
also failed to uncover the conspiracy’s cocaine source and the extent
to which the coconspirators distributed it for resale.

   This showing was sufficient. We have recognized that at times,
wiretaps "are necessary tools of law enforcement, . . . particularly
where crimes are committed by large and sophisticated organiza-
tions." Id. at 221-22. Courts must be careful not to read the statute in
"an overly restrictive manner," id. at 853, which could result in help-
ing insulate more complex and sophisticated conspiracies. In short,
the Government here made a sufficient showing that wiretaps were
necessary to reach the ultimate goals of the investigation. They also
provided the court with ample information to support that showing.
"In these circumstances, we [have] decline[d] to disturb the district
court’s conclusion that such surveillance was necessary to probe a
conspiracy that might otherwise have proved impossible to [thor-
oughly] penetrate." Id. Accordingly, the issuing court did not abuse
its discretion in authorizing the wiretaps, and the district court did not
err in denying Appellants’ motion to suppress.

                                   VI.

   Appellants make two arguments with respect to the sufficiency of
the evidence. First, Wilson argues that there was insufficient evidence
from which to conclude that he possessed a firearm on September 14,
2002. Second, Appellants (especially Powell) argue that the evidence
was insufficient to support the jury’s conclusion that they were
involved in a conspiracy to distribute cocaine and crack cocaine.

   When addressing sufficiency of the evidence challenges, we must
affirm the jury’s verdict "if there is substantial evidence, taking the
view most favorable to the Government, to support it." Glasser v.
                       UNITED STATES v. WILSON                       21
United States, 315 U.S. 60, 80 (1942). "[S]ubstiantial evidence is evi-
dence that a reasonable finder of fact could accept as adequate and
sufficient to support a conclusion of a defendant’s guilt beyond a rea-
sonable doubt." United States v. Burgos, 94 F.3d 849, 862 (1996) (en
banc). Thus, "we shall reverse a verdict [only] if the record demon-
strates a lack of evidence from which a jury could find guilt beyond
a reasonable doubt." Id.

                                  A.

   Wilson argues that there was insufficient evidence linking him to
the firearm found in the master bedroom in the Tamar Drive apart-
ment because the firearm was found in the master bedroom, which he
contends belonged to Dieter Munz. Wilson further contends that the
firearm could not be connected to him because the apartment was
rented in Munz’s name. The Government, on the other hand, argues
that the master bedroom contained evidence that tended to show that
the bedroom was shared by Wilson and Munz.

   In the same night stand in which the gun was found, police uncov-
ered a drug tally sheet that they believed belonged to Wilson; the tally
sheet had the names of dealers who purchased crack cocaine directly
from Wilson. Police also found a traffic violation citation in Wilson’s
name, as well as a prisoner property inventory report with Wilson’s
name and picture. There was also an envelope full of photos of Wil-
son and Powell on vacation. Four days later, Wilson was seen moving
furniture out of the apartment. Hicks also testified that Wilson told
him that he had moved out of his Howard County apartment because
it had been raided by police.

   Viewing all this evidence in the light most favorable to the Govern-
ment, as we must, the jury’s verdict was reasonable. The Government
only had to prove that Wilson’s possession was constructive, meaning
that he "exercised, or had the power to exercise, dominion and control
over the" firearm. United States v. Jackson, 124 F.3d 607, 610 (4th
Cir. 1997) (finding the evidence sufficient to convict defendant of
constructively possessing a gun that was recovered from his mother’s
house after a domestic disturbance call). When examining all the evi-
dence connecting Wilson to the master bedroom at the Tamar Road
apartment in the light most favorable to the Government, we cannot
22                    UNITED STATES v. WILSON
say that there was "a lack of evidence from which a jury could find
guilt beyond a reasonable doubt." Burgos, 94 F.3d at 862.

                                 B.

   Appellants argue that the evidence only showed that Murray, Wil-
son, and Powell may have dealt drugs as individuals and that the three
men knew each other, but did not go so far to show that they con-
spired together to distribute narcotics. The evidence with respect to
Wilson and Murray’s connection in the conspiracy was so over-
whelming that it merits no further discussion, and in fact, Appellants
barely lift a finger in arguing otherwise. Powell, on the other hand,
argues more forcefully that the evidence was insufficient to show that
he had entered into the criminal conspiracy. Nonetheless, his argu-
ment has little merit.

   Recorded conversations between Powell and his coconspirators
proved beyond a reasonable doubt that Powell was connected to the
existing conspiracy. When these conversations are viewed in the light
most favorable to the Government, there is no doubt that Powell had
entered into an agreement to distribute narcotics. Consider, for exam-
ple, portions of a conversation between Murray and Powell that
occurred on June 6, 2003:

     Powell: Got to give him some money we about to jump off
     any way. You know what I am saying, but still we making
     extra money anyway through Ed, you know what I am say-
     ing. Charging nine hundred for these ounces, we making
     extra money you what I am saying.

     Murray: Yep, that’s why I ain’t tripping . . . .

     Powell: We going make, we going make, at least make
     some of money back . . . .

     Murray: I know.

     **************

     Powell: I got a like a stack on me.
                       UNITED STATES v. WILSON                       23
    Murray: Oh we good.

    Powell: Cause [people] going to be hollering today . . . .

    Murray: Longs make sure, longs we got 7 at the end of the
    tally we good.

    Powell: What seven, oh, oh you talking about after the
    show?

    Murray: No I am talking about, I’m talking about our
    work, our street shit.

    **************

(J.A. at 2093-94 (emphasis added).)

   Beyond the recorded conversations, there was damning evidence
against Powell in the form of testimony from Anderson Hicks. Hicks
stated that Powell provided him with drugs after his arrest, and more
importantly, that Powell alerted Wilson of the impending police raid
that led to Wilson’s arrest at the Old Court Road apartment. Powell
attempts to mitigate Hicks’s testimony by arguing that it, "particularly
as it relates to Powell, was not trustworthy." (Appellants’ Reply Br.
at 8.)

   This argument, however, misunderstands this court’s role in
reviewing the sufficiency of the evidence. "In applying this standard
of review, we must remain cognizant of the fact that the jury, not the
reviewing court, weighs the credibility of the evidence and resolves
any conflicts in the evidence presented, and if the evidence supports
different, reasonable interpretations, the jury decides which interpre-
tation to believe." Burgos, 94 F.3d at 862 (internal quotation marks
and alterations omitted). Thus, "determinations of credibility are
within the sole province of the jury and are not susceptible to judicial
review." Id. at 863 (internal quotation marks omitted); see United
States v. Saunders, 886 F.2d 56, 60 (4th Cir. 1989) (holding that we
are "bound by the credibility choices of the jury" (internal quotation
marks omitted)).
24                     UNITED STATES v. WILSON
   "[U]pon establishing the conspiracy, only a slight connection need
be made linking a defendant to the conspiracy to support a conspiracy
conviction, although this connection also must be proved beyond a
reasonable doubt." Burgos, 94 F.3d at 862. "[A] defendant need not
know all of his coconspirators, comprehend the reach of the conspir-
acy, participate in all the enterprises of the conspiracy, or have joined
the conspiracy from its inception." Id. at 861. Hicks’s testimony,
when combined with the recorded conversations between Powell and
his coconspirators, proved beyond a reasonable doubt that Powell was
connected to the existing conspiracy. The evidence was therefore suf-
ficient to support Powell’s conspiracy conviction.

                                  VII.

   For the foregoing reasons, Appellants’ convictions and sentences
are affirmed.

                                                            AFFIRMED
