NOT PRECEDENTIAL

                       UNITED STATES COURT OF APPEALS
                            FOR THE THIRD CIRCUIT
                                 _____________

                                     No. 16-3225
                                    _____________

                           UNITED STATES OF AMERICA

                                            v.

                             ALEXANDER RODRIGUEZ,
                                   a/k/a Alex

                                 Alexander Rodriguez,
                                                 Appellant

                                    ______________

                    On Appeal from the United States District Court
                            for the District of New Jersey
                     (D.C. Crim. Action No. 1:13-cr-00428-001)
                     District Judge: Honorable Robert B. Kugler
                                   ______________

                     Submitted Under Third Circuit L.A.R. 34.1(a)
                                 October 27, 2017
                                 ______________

 Before: GREENAWAY, JR., COWEN, Circuit Judges, and PADOVA, District Judge*

                            (Opinion Filed: March 14, 2018)
                                   ______________




      *
         The Honorable John R. Padova, Senior United States District Judge for the Eastern
District of Pennsylvania, sitting by designation.
                                        OPINION**
                                      ______________
PADOVA, Senior District Judge.

       Alexander Rodriguez appeals his conviction, after a jury trial, of one count of

conspiracy to distribute and possess with intent to distribute more than 500 grams of

methamphetamine. He raises three claims of error. First, he argues that the District Court

failed to properly instruct the jury with respect to the alibi defense he presented at trial.

Second, he contends that the Government’s proof at trial varied from the conspiracy

charged in the Indictment, and thereby prejudiced Rodriguez’s right to a fair trial. Finally,

he maintains that one of the Government’s expert witnesses introduced irrelevant and

prejudicial testimony concerning the manufacture and effects of methamphetamine.

Because we conclude, for the reasons set forth below, that none of these claims amount to

plain error, we will affirm.

                                      I. Background

       Because we write primarily for the benefit of the parties, we recite only those facts

necessary to our analysis. Rodriguez was charged in a one count Indictment of conspiring

from April 1 to April 28, 2012 to distribute, and possess with the intent to distribute, more

than 500 grams of methamphetamine in violation of 21 U.S.C. § 846. On March 6, 2015,

a jury convicted him of that count.

       The charge arose from Rodriguez’s participation in the sale of four pounds of


       **
         This disposition is not an opinion of the full Court and pursuant to I.O.P. 5.7 does
not constitute binding precedent.
                                             2
methamphetamine to a group of buyers, and his role in assisting the buyers to dilute the

drugs for subsequent resale. The evidence admitted at trial established that Rodriguez

arranged with his friend, David Santos, to supply methamphetamine to a group of three

buyers: Kate Rodriguez, Joel Rodriguez, and David Crespo.1 Rodriguez brokered a deal

between the buyers and Santos, whereby Kate, Joel, and Crespo agreed to pay $100,000.00

in exchange for four pounds of methamphetamine. Santos acquired the drugs from a

connection he had identified only as “Juko,” and realized a $10,000.00 profit from the sale,

half of which he gave to Rodriguez. The sale took place on the evening of April 17, 2012

at Santos’s house; Rodriguez met with Kate and Joel beforehand, took them to Santos’s

house, and left with them after the deal was completed. Rodriguez also met with Joel for

several hours the next day, April 18, 2012, to dilute one pound of the methamphetamine

into five diluted pounds.       Rodriguez took possession of the remaining undiluted

methamphetamine, while Joel kept the five diluted pounds of drugs to take to Florida to

sell with Kate.

       Kate and Joel were ultimately arrested during the trip to Florida, and cooperated

with the Drug Enforcement Administration (“DEA”) in its investigation. The DEA

executed a search warrant on the house next door to Santos’s after Kate mistakenly

identified it as the location where they had purchased the drugs, which prompted Santos to


       1
          Appellant is not related to Kate Rodriguez or Joel Rodriguez. Thus, for the sake
of clarity, and to match the procedure at trial, we refer to Kate and Joel by their first names
and refer to Appellant by his last name.

                                              3
warn Rodriguez of the law enforcement activity. Santos, Crespo, and Rodriguez were

subsequently indicted for their roles in the conspiracy.

                                   II. Standard of Review

        The District Court had jurisdiction under 18 U.S.C. § 3231. This Court has

jurisdiction over Rodriguez’s appeal pursuant to 28 U.S.C. § 1291. Rodriguez concedes

that he did not preserve below any of the issues he now raises on appeal, and we

consequently review his claims for plain error. Fed. R. Crim. P. 52(b); United States v.

Olano, 

, 733-36 (1993). We have the discretion to correct an error not raised

below

               only where the appellant demonstrates that (1) there is an
               “error”; (2) the error is “clear or obvious, rather than subject to
               reasonable dispute”; (3) the error “affected the appellant’s
               substantial rights, which in the ordinary case means” it
               “affected the outcome of the district court proceedings”; and
               (4) “the error seriously affect[s] the fairness, integrity or public
               reputation of judicial proceedings.”

United States v. Marcus, 

, 262 (2010) (quoting Puckett v. United States, 

, 135 (2009)) (alteration in original) (additional citations omitted).

                                         III. Analysis

A. The District Court’s Alibi Instruction

        The first issue Rodriguez raises on appeal concerns the instruction the District Court

gave to the jury concerning his alibi defense. The proof at trial established that Rodriguez

was present during two events relating to the conspiracy: first, the sale of the

methamphetamine from Santos to Joel and Kate, which took place at Santos’s house the
                                                4
evening of April 17, 2012, and second, the meeting between Joel and Rodriguez on April

18, 2012, during which they diluted the methamphetamine purchased the previous day.

Rodriguez presented two witnesses, his mother and the mother of his child, who each

testified that he was with the two them at the Rodriguez family home from the evening of

April 17 through approximately 2:00 p.m. on the afternoon of April 18, 2012. On the basis

of this testimony, Rodriguez requested that the District Court give the jury an alibi

instruction.    The Government objected to the use of the Third Circuit Model Jury

Instruction, arguing that it misstated the law when applied to a drug distribution conspiracy

charge because the Government was not required to prove Rodriguez’s presence at any

particular place in order to establish the elements of conspiracy. 2 The District Court

proposed an alternate instruction, noting its intention to omit any reference to any particular


       2
           The Third Circuit Model Jury Instruction for an alibi defense states as follows:

                [Name] has raised a defense of alibi to Count[s] [Nos.] of the
                indictment, and you have heard evidence that [name] was not
                present at the time and place where the offense[s] charged is
                [are] alleged to have been committed. The government has the
                burden to prove beyond a reasonable doubt each of the
                elements of the offense[s], including that [name] was present
                at the time and place where the offense is alleged to have
                occurred. [Name] does not have to prove an alibi or that [he]
                [she] was not present.
                If, after considering all the evidence in this case regarding
                Count[s] [Nos.] of the indictment, you have a reasonable doubt
                about whether [name] was present at the time and place where
                the offense[s] charged was [were] committed, you must find
                [name] not guilty of that [those] offense[s].

Third Circuit Crim. Jury Instructions, § 8.02 (2009) [hereinafter, Model Instructions].
                                               5
factual scenario and to permit the parties to argue the factual contours of the alibi to the

jury. Rodriguez did not object to the proposed instruction. The District Court’s entire

instruction concerning the alibi defense was: “Alexander Rodriguez has raised a defense

of alibi. The Government has the burden to prove beyond a reasonable doubt each of the

elements of the offense. Alexander Rodriguez does not have to prove an alibi.” App. at

1336.

        Rodriguez argues on appeal that the District Court’s alibi instruction was deficient

because it did not specify, as the law requires, that the Government had the burden to prove

beyond a reasonable doubt that Rodriguez’s alibi was not true, and that Rodriguez needed

only to raise a reasonable doubt about his presence at the scene of the offense to be entitled

to an acquittal. He further argues that the District Court’s deficient instruction made it “all

but inevitable” that the jury was confused as to the burden of proof and was likely to have

used any failure to prove his alibi as evidence of his guilt. Appellant’s Br. 25. In this case,

we conclude that the failure to use the language included in the model alibi instruction was

not plain error.

        Our precedent has long made clear that, where a defendant has raised an applicable

defense of alibi, the “defendant is entitled to a specific instruction that ‘on the issue of alibi,

the government ha[s] to convince the jury beyond a reasonable doubt that the alibi was not

true.’” United States v. Simon, 

, 1243 (3d Cir. 1993) (quoting United States

v. Booz, 

, 723 (3d Cir. 1971)) (alteration in original) (additional citation

omitted). This specific instruction is necessary “because ‘the jury is likely to become
                                                6
confused about the burden of proof when an appellant offers . . . [alibi] evidence.’” 

451 F.2d at 723).       However, other circuits have noted that such an

instruction may not be necessary when the defendant’s presence at the scene of the crime

is not a required element of the offense. See United States v. Bryser, 

, 87 (2d

Cir. 1992) (concluding that there “was no basis for an alibi instruction” where the

prosecution did not have to prove the defendants’ presence at the scene of the theft “in

order for the jury to convict the defendants of conspiring to commit mail fraud, wire fraud,

and theft from an interstate shipment” (citation omitted)); United States v. Lee, 

, 970 (5th Cir. 1973) (holding that district court was not required to give an alibi

instruction because “[t]he alibi, if believed by the jury, established no more than that [the

defendant] was not present at the time that one or more of the conspirators performed an

overt act in furtherance of the conspiracy”). The comments to the alibi defense model jury

instruction in this circuit similarly acknowledge that a specific alibi instruction is not

necessary “[f]or some offenses, such as conspiracy” because “there may not be a specific

time and place when and where the offense was committed, and therefore the defense of

alibi may be inapplicable.” Model Instructions § 8.02 cmt. at 754.

       Rodriguez argues that the District Court’s alibi instruction was erroneous because

it did not tell the jurors that the Government had the burden to prove that Rodriguez was

present at the drug sale on April 17, 2012 and the meeting to dilute the methamphetamine




                                             7
on April 18, 2012.3 We reject this argument because the Government was not required to

prove Rodriguez’s presence at either event in order to meet its burden of proof on the

elements of the conspiracy with which he was charged. In order to meet its burden of proof

for the charged conspiracy, the Government needed to establish “(1) a shared unity of

purpose between the alleged conspirators, (2) an intent to achieve a common goal, and (3)

an agreement to work together toward that goal.” United States v. Bailey, 

, 108

(3d Cir. 2016) (citing United States v. Gibbs, 

, 197 (3d Cir. 1999)). Thus, the

Government was not required to “prove the commission of any overt acts in furtherance of

[a] conspiracy” to distribute drugs in violation of 21 U.S.C. § 846. United States v.

Shabani, 

, 15 (1994) (citation omitted). Because the Government was not

required to prove that Rodriguez participated in any overt acts, his alibi, if believed by the

jury, would only serve to demonstrate that he did not participate in the April 17, 2012 sale

or the April 18, 2012 meeting to dilute the drugs, but would not entitle him to acquittal on

the conspiracy charge.

       Although a significant portion of the proof at trial focused on Rodriguez’s presence


       3
         Rodriguez also argues that the District Court’s instruction was deficient because,
in the absence of a specific instruction to the contrary, it “was all but inevitable” that “the
jury would construe a failure of proof of the alibi by [Rodriguez] as evidence of his guilt.”
Appellant’s Br. 25. However, the District Court’s alibi instruction made clear that
“Rodriguez does not have to prove an alibi,” App. at 1336, language which is effectively
identical to the portion of the model instruction addressing the defendant’s burden of proof.
See Model Instructions § 8.02 (“[Name] does not have to prove an alibi or that [he] [she]
was not present.”). We therefore conclude that the District Court’s instruction was not
erroneous insofar as Rodriguez maintains that it failed to instruct the jury that it could not
construe any failure to prove his alibi as evidence of his guilt.
                                              8
at and participation in the sale and later dilution of the methamphetamine, the Government

also produced evidence of Rodriguez’s involvement in the conspiracy beyond those events.

This evidence included testimony by Santos and Kate that Rodriguez had communicated

on multiple occasions with each of them to arrange the sale. The Government also

produced evidence that Rodriguez was in regular cell phone contact with the other

members of the conspiracy on the day of the sale, with the exception of an hour-long gap

from 9:53 to 10:58 p.m. Finally, the Government also presented evidence that Rodriguez

was involved with the conspiracy after April 18, 2012, including testimony by Santos that

he met with Rodriguez to warn him after the DEA searched Santos’s neighbor’s house and

evidence that Rodriguez called Joel and Kate twenty-two times in rapid succession the

evening they were arrested with the drugs.

       Given this other relevant evidence of Rodriguez’s involvement in the conspiracy, it

is clear that if it had given the model jury instruction for an alibi defense, “the district court

could have misled the jury.” 

. The jurors might have erroneously

believed that, if the Government failed to prove Rodriguez’s presence at either the sale or

the dilution meetings, they would be required to acquit on the charge of conspiracy, even

if they believed all of the other evidence of Rodriguez’s involvement. Accordingly, we

reject Rodriguez’s argument that the District Court erred by failing to give a jury

instruction that would have placed a burden on the Government to prove his presence at

the meetings on April 17 and 18, 2012 beyond a reasonable doubt.


                                                9
B. The Scope of the Conspiracy Proved at Trial

       In his second appellate issue, Rodriguez claims that the Government’s trial evidence

did not support the existence of the single conspiracy charged in the Indictment, but instead

demonstrated that multiple, unrelated conspiracies existed, and, consequently, the evidence

amounted to a variance from the Indictment. Rodriguez contends that this variance

prejudiced his right to a fair trial because it created a risk that the jury’s verdict was not

unanimous insofar as the jurors may not have agreed on which of the unrelated conspiracies

he joined.

       The Indictment charged that Rodriguez, Crespo, Santos, and unnamed other

individuals conspired to distribute and possess with the intent to distribute more than 500

grams of methamphetamine. Rodriguez argues that the evidence presented at trial showed

that two distinct conspiracies existed: (1) a supplier conspiracy among Rodriguez, Santos,

and Juko, the purpose of which was to sell methamphetamine to Kate, Joel, and Crespo;

and (2) a separate diluting/reselling conspiracy among Joel, Kate, Crespo, and Rodriguez,

the purpose of which was to dilute the methamphetamine and profit from the distribution

of the diluted drugs to buyers in Florida.

       “The ‘variance doctrine is intended to prevent a situation in which the jury might be

unable to separate offenders and offenses and easily could transfer the guilt from one

alleged co-scheme[r] to another.’” United States v. Greenidge, 

, 93 (3d Cir.

2007) (quoting United States v. Barr, 

, 648 (3d Cir. 1992)). A variance exists

“if the indictment charges a single conspiracy while the evidence presented at trial proves
                                             10
only the existence of multiple conspiracies.” United States v. Kemp, 

, 287 (3d

Cir. 2007) (citing United States v. Kelly, 

, 258 (3d Cir. 1989)). “We must

determine ‘whether there was sufficient evidence from which the jury could have

concluded that the government proved the single conspiracy alleged in the indictment.’”

892 F.2d at 258). “We will sustain the jury’s verdict if there is

substantial evidence, viewed in the light most favorable to the Government, to support a

finding of a single conspiracy.” United States v. Perez, 

, 345 (3d Cir. 2002)

(citing United States v. Smith, 

, 200 (3d Cir. 1986)).

       In determining whether the evidence presented at trial establishes the existence of a

single conspiracy or multiple independent conspiracies, we consider three factors: “(1)

‘whether there was a common goal among the conspirators’; (2) ‘whether the agreement

contemplated bringing to pass a continuous result that will not continue without the

continuous cooperation of the conspirators’; and (3) ‘the extent to which the participants

overlap in the various dealings.’” 

(quoting 

).

However, the absence of any one of these factors is not dispositive. 

(quoting United States v. Padilla, 

, 115 (3d Cir. 1992)). Moreover,

“[t]he Government need not prove that each [conspirator] knew all of the conspiracy’s

details, goals, or other participants” in order to demonstrate the existence of a single overall

conspiracy. 

(citing United States v. Theodoropoulos, 

,

593 (3d Cir. 1989)). A defendant cannot demonstrate the existence of a variance merely

by proving that a master conspiracy encompassed distinct sub-schemes; sub-schemes that
                                              11
are related “in support of the overall illegal scheme” are not independent conspiracies. 

Accordingly, proof of “interdependence [among coconspirators] serves as evidence

of an agreement” that “helps establish whether the alleged coconspirators are all committed

to the same set of objectives in a single conspiracy.” Kemp, 

(internal

quotations and citations omitted).

       Rodriguez contends that the proof at trial indicated that there were two unrelated

conspiracies that lacked a common goal: the conspiracy between Juko and Santos to

distribute methamphetamine, and the conspiracy among Kate, Joel, and Crespo to dilute

and resell the drugs in Florida. Rodriguez argues that, because the jury could have

concluded that he joined either or both of these conspiracies, but the Indictment charged

only one overall conspiracy, the proof at trial amounted to a variance from the Indictment.

We disagree. Viewing the evidence in the light most favorable to the Government, we

conclude that the evidence admitted at trial does not support the existence of two distinct

conspiracies.

       There was sufficient evidence for the jury to conclude that Rodriguez, Santos, Joel,

Kate, and Crespo were all members of a single conspiracy because they shared a common

goal and were dependent upon each other’s continuous cooperation for the success of the

undertaking. It is clear that the conspirators, including Rodriguez, had a common goal to

conduct a transaction involving the sale of four pounds of methamphetamine from Santos

to Joel, Kate, and Crespo. This was not a situation where the evidence at trial established

two distinct groups, which operated without knowledge of each other, and which each had
                                            12
dealings with Rodriguez. Rather, Santos was aware before the transaction that Rodriguez

was acting as a middleman, arranging for buyers of his product, and Kate was aware in

advance that Rodriguez was arranging for the purchase of the methamphetamine from

another individual. It is also clear that the success of this venture was dependent upon the

continuous cooperation of all the parties charged in the indictment: Santos only sought to

obtain the drugs because Rodriguez knew that Kate, Joel, and Crespo were interested

buyers, and the buyers’ scheme to profit from the resale of the drugs could not have

succeeded had Santos been unable to provide them. This cooperation culminated in the

sale Rodriguez orchestrated on the evening of April 17, 2012, when Joel and Kate, using

money provided by Crespo, purchased the methamphetamine from Santos.

       Rodriguez argues that Joel, Kate, and Crespo’s purchase of the drugs from Santos

does not amount to a drug distribution conspiracy because they were “mere buyer[s] whose

limited dealings” with Santos were insufficient to make out a distribution conspiracy with

Santos. Appellant’s Br. 33. Rodriguez relies on the proposition that “simple buyer-seller

relationship[s],” without more, are insufficient to amount to a conspiracy to distribute

drugs. United States v. Gibbs, 

, 197 (3d Cir. 1999) (citations omitted); see

also United States v. Pressler, 

, 152-53 (3d Cir. 2001) (discussing Gibbs).

This proposition, however, is simply inapplicable to the instant appeal. The evidence

presented at trial established that the April 17, 2012 transaction was the result of extensive

dealings among the parties that were conducted through Rodriguez. Moreover, Rodriguez

had a stake in both sides of the transaction, first splitting the proceeds of the sale with
                                             13
Santos and then assisting Joel to dilute the methamphetamine for resale. Rodriguez’s role

as the orchestrator of and conduit between the parties to the transaction is sufficient to

distinguish this case from that of a “simple buyer-seller” interaction. 

.

       Even if we were to accept Rodriguez’s assertion that there were two distinct

schemes, namely, the supplying scheme between himself, Juko, and Santos and the

reselling scheme between himself, Kate, Joel, and Crespo, we find that there is sufficient

evidence for a reasonable jury to find that those schemes were interdependent, and

consequently part of a single, larger conspiracy. The evidence demonstrated that Joel,

Kate, and Crespo did not initially seek to deal in methamphetamine, and only undertook to

buy, dilute, and attempt to resell it because Rodriguez told them that Santos could obtain

methamphetamine.       Similarly, the evidence showed that Santos acquired the

methamphetamine specifically because Rodriguez told him he had people, Kate, Joel, and

Crespo, “lined up” to buy it. App. at 514. In short, the participants all knew that others

were also participants and that the success of each undertaking depended upon the

willingness and agreement of the participants in the other. See 

.

Consequently, we conclude that there was substantial evidence to support the jury’s finding

of a single drug distribution conspiracy between Rodriguez, Santos, Crespo, and others.

Accordingly, we reject Rodriguez’s argument that there was a variance between the

conspiracy charged in the Indictment and the proof of that conspiracy at trial.

Consequently, we conclude that the District Court did not commit plain error in connection
                                            14
with the evidence of the conspiracy admitted at trial.

C. The Expert’s Testimony

       Finally, Rodriguez claims that the District Court erred by not excluding certain

testimony by an expert witness for the Government concerning the manufacture and effects

of methamphetamine because that testimony was irrelevant and prejudicial under Federal

Rules of Evidence 401 and 404(b). At trial, the Government offered the testimony of DEA

Special Agent Mark Wassmuth as an expert in the “manufacture, use, abuse and

distribution of methamphetamine.” App. at 100. In the course of his testimony, Agent

Wassmuth testified about his experience with the manufacture of methamphetamine in labs

and the dangers inherent in the creation of the drug. Agent Wassmuth also described his

experience and opinions regarding the physical impact of methamphetamine on a user, the

outward manifestations of such use, and the differences between the effects of

methamphetamine and cocaine. Agent Wassmuth further testified about how and with

what substances methamphetamine could be diluted by an inexperienced person.

Rodriguez did not object at trial to Agent Wassmuth’s qualifications or any of his

testimony. However, he now contends that certain testimony concerning the dangers of




                                             15
manufacturing4 and consuming5 methamphetamine should have been excluded at trial


      4
        Rodriguez contends that the District Court should have excluded the following
testimony concerning the manufacture of methamphetamine:

      Q. With regard to the safety factor, have you, in your experience, on this
         clandestine lab enforcement scheme come upon labs that are, for lack of
         a better term, in crisis?
      A. Some are – meaning that they may not be very sophisticated or –
      Q. Well, no, in terms of it being volatile to the point of the lab itself being in
         a crisis mode?
      A. Absolutely. There – sometimes you stumble on labs that are active labs.
         They’re actively cooking, as we say. Some are not, not operational,
         whatsoever. Some are literally in a box on the floor. But they’re all
         considered laboratories and they’re all dangerous. But usually, when we
         enter a lab, we don’t turn on lights, we don’t turn on any switches.
         Nothing – do nothing that you would maybe normally do in a normal
         search warrant.
      Q. Have you, in you experience, come upon any individual who is cooking
         apparently methamphetamine who has, as a result of error, caused himself
         to be in the process of being either harmed, consumed, et cetera?
      A. Yes, I have. A few years ago in Somers Point, New Jersey, I got a phone
         call late one night. I responded to the scene and it was the result of what’s
         known as a one-pot lab. A one-pot lab is fairly new. It’s probably about
         five or six years old.         This is a particular method of making
         methamphetamine using a one pot, a one bottle, usually one liter size
         plastic jugs and it’s all cooked into, into one pot one – this one jug, but
         it’s – the problem with it is that it’s highly flammable, because it uses
         lithium metal mixed with water, which is flammable instantly.
         Most of these people that do this procedure are very inexperienced. It
         can be found on the internet, very dangerous. The individual that did do
         this exploded in his kitchen, he caught fire and in the midst of him being
         on fire, he literally rushed outside to discard the contents left from it into
         the dumpster. He had third-degree burns, was in the hospital for a month
         for internal damage – internal injuries to his lungs.

App. at 96-98.
      5
         Rodriguez further argues that the District Court should have excluded the
following testimony concerning the effects of methamphetamine use:
                                             16
      Q. And as a result of [your past investigations], have you been able to, in
         addition to your training, determine how methamphetamine effects users?
      A. Yes, absolutely.
      Q. And in what regard?
      A. The – the physical effects are very strange, in that the methamphetamine
         is not a natural substance. Cocaine comes from the coca plant, a natural
         substance. Methamphetamine is purely chemicals and it affects the body
         in such a way that’s different than many other drugs. A lot of increased
         – because it’s a central nervous system stimulant, it increases blood
         pressure, dilated pupils. There’s instance, higher instance of acne and
         tooth decay. It affects the body in that way. It’s general irritability, and
         you can’t sleep, insomnia.

App. at 99.

      Q. Okay. Have you seen the effects of methamphetamine on individuals that
         you would be either interviewed, arrested, been part of your
         investigations?
      A. I have, yes.
      Q. And could you tell us just briefly what you’ve observed with regard to
         that?
      A. Some longer term meth users, long-term use of methamphetamine there’s
         the experience that they have bugs under their skin and subsequently what
         happens is they start picking at their skin – they call them crank bugs.
         One of the terms for meth is crank. So they feel like they have this
         sensation of something crawling under their skin. So it creates open
         sores. They’re generally not very interested in personal hygiene.
         A tweaker is somebody that maybe would stay up for days and days and
         days. And 15 days is not really out of the norm for a heavy meth user.
         Tooth decay, because they’re, again, not interested in any kind of
         hygiene, plus methamphetamine drys out your mouth and it promotes
         tooth decay. If you were to go on the internet and Google faces of meth,
         you would actually see – and Google meth mouth, it will talk about tooth
         decay. Oftentimes meth users, the only thing they are interested in is
         getting high again and looking where they’re going to get meth again and
         personal hygiene goes out the window. So the only thing they are
         consuming, it’s not healthy food, it’s snacks and sweets and garbage food.
         And that doesn’t help their body either.
                                            17
because they were irrelevant and prejudicial.

       Federal Rule of Evidence 702 controls the admission of testimony by expert

witnesses, and provides in relevant part that an expert may offer testimony in the area of

his or her expertise if “the expert’s scientific, technical, or other specialized knowledge

will help the trier of fact to understand the evidence or to determine a fact in issue.” Fed.

R. Evid. 702(a). “The basic approach to opinions, lay and expert, in [the Federal Rules of

Evidence] is to admit them when helpful to the trier of fact.” 

(quoting Fed. R. Evid. 704 advisory committee note). The question of whether expert

testimony will be helpful to a jury is one of relevance, and is “evaluated under the standard

expressed in [Federal] Rule [of Evidence] 401.” United States v. Ford, 

, 218




       Q. With regard to a difference between methamphetamine and cocaine, in
          your experience, which high lasts longer, if you’re able to determine that?
       A. Methamphetamine, because it’s so strong, because it’s a different kind of
          stimulant, lasts anywhere from eight to 24 hours. It can last a long period
          of time. Cocaine, anywhere from 20 minutes, maybe up to two hours.
          It’s a longer acting – or a quick acting substance. Methamphetamine is
          longer acting and it’s longer acting if it’s specifically injected or smoked.

App. at 104-05.

       Q. And one final question. Earlier, you said that it can be abused and in your
          experience, how addictive is meth, as opposed to perhaps cocaine or
          heroin?
       A. It is probably just as addictive, and every person is different, every
          individual is different to what their addiction levels may be. Some people
          maybe might not get addicted right away and some are more. But it is a
          highly addictive substance very similar to cocaine and heroin.

App. at 108.
                                             18
(3d Cir. 2007) (citations omitted). Accordingly, expert testimony is helpful to the jury if it

has “any tendency to make a fact more or less probable than it would be without” the

testimony and “the fact is of consequence in determining the action.” Fed. R. Evid. 401.

       Rodriguez argues that the District Court erred in allowing Agent Wassmuth to

testify concerning the dangers associated with the manufacture of methamphetamine and

its effects on users because neither the creation nor the use of methamphetamine was at

issue in the case. Rather, Rodriguez maintains, the only issues for the jury to decide were

whether there was a conspiracy to distribute drugs and whether he had joined that

conspiracy. We agree that these areas of the expert’s testimony were not helpful to the jury

in resolving the issues at trial.6

       We nevertheless conclude that the admission of this testimony did not amount to

plain error because Rodriguez has not demonstrated that it affected his substantial rights.

Rodriguez argues that this testimony was prejudicial because it amounted to an


       6
          The Government argues that this was helpful to the jury for two reasons: first,
Agent Wassmuth’s account of searching methamphetamine labs was a part of his testimony
regarding his expert qualifications, and that without this testimony he could not have been
qualified as an expert; second, it argues that the opinions comparing the effects of
methamphetamine to cocaine were relevant because Rodriguez made the nature of
methamphetamine an issue in his opening statement. We disagree. First, an expert is not
entitled to testify to irrelevant experiences in the course of providing a basis to be qualified
as an expert because Rule 702 controls the scope of both his qualifications and his
testimony to support his expertise. Under the circumstances of this case, neither the
expert’s experience with nor his potential expertise in the dangers presented by the
production of methamphetamine was helpful to the jury. Second, comments made by
Rodriguez’s counsel in his opening statement that “[m]eth is a funny drug” and that one
would have to be a chemist to either make or cut it did not make the addictive nature of
methamphetamine or its physical effects on a user an issue at trial. App. at 82-83.
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inappropriate “back door” attack on his character, in violation of Federal Rule of Evidence

404(b). Appellant’s Br. 44-45. However, Agent Wassmuth’s testimony did not address

Rodriguez’s character as an individual. The expert testified about the production and

effects of methamphetamine in general, but did not offer any testimony concerning

Rodriguez or the particular drugs seized in his case. Moreover, the Government did not

rely on the agent’s improper testimony in its closing argument, nor did it encourage the

jury to use the expert’s testimony as a basis to impugn Rodriguez’s character. We therefore

reject this argument because Rodriguez has not established that the District Court’s

admission of these specific portions of the expert’s testimony “affected the outcome of the

district court proceedings,” and accordingly has not established that the admission of that

testimony was plain error that affected his substantial rights. 

(quotation omitted).

                                     IV. Conclusion

       For the foregoing reasons, we conclude that Rodriguez has not met his burden to

demonstrate that the District Court’s alibi instruction amounted to plain error, that there

was any variance between the conspiracy charged in the Indictment and the proof of that

conspiracy at trial that amounted to plain error, or that the admission of the testimony of

the Government’s expert witness amounted to plain error. We will therefore affirm the

District Court’s judgment of conviction.




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