Affirmed by published opinion. Judge LUTTIG wrote the opinion, in which Judge MURNAGHAN and Judge MICHAEL joined.
OPINION
Shaheem and Raheem Johnson were convicted on nineteen counts related to their drug conspiracy, in furtherance of which they murdered five people. They now appeal their convictions. Finding no reversible error, we affirm.
I.
On June 4, 1998, appellants Shaheem and Raheem Johnson, identical twin brothers, were charged in federal district court with conspiracy to distribute cocaine; murder in aid of racketeering; murder using a firearm during a drug trafficking offense; and possession of a firearm by a convicted felon. Shaheem was charged with engaging in a continuing criminal enterprise; conspiracy to commit money laundering; carrying a firearm during a drug trafficking offense; distribution of cocaine base; and possession with intent to distribute cocaine base. Raheem was charged with murder in aid of racketeering; and murder using a firearm during a drug trafficking offense.
In a trial that lasted seven weeks, the government presented testimony and evidence that demonstrated that Shaheem, Raheem, and others organized a large-scale drug operation. The Johnsons obtained cocaine from New York and Maryland, and distributed it in Ohio, Virginia, North Carolina, and Maryland. The government showed that in early 1992, Sha-heem started the drug enterprise, and Raheem soon took over part of the distribution for his brother. They used numerous couriers and cars, titled in various names, to transport drugs, weapons, and cash.
The government also presented testimony and evidence that showed that Sha-heem and Raheem were involved in five murders related to their conspiracy, as follows. On July 30,1995, Raheem, Shawn Thomas, and Antonio Stevens drove to Philadelphia together, where Raheem, who believed Stevens had stolen his money, shot and killed Stevens. In March 1996, Raheem, Shaheem, and others shot and killed Bernard Franklin, whom Shaheem believed had robbed his residence and attacked his girlfriend. In December 1996, Shaheem and Raheem hired Eldon Brown to kill Richard Villa, whom they believed was planning to steal from them. And, in March 1997, Raheem and Rickey Piranti murdered Shawn Thomas and his girlfriend, Tracy Morgan. Because Thomas had recently been arrested, Raheem feared Thomas might incriminate Raheem in order to make a deal with the police on his own charges.
Shaheem and Raheem were both convicted on all counts charged except that as to their joint murder counts, Shaheem was found guilty of voluntary manslaughter and Raheem was found guilty of second degree murder. Both Shaheem and Ra-heem were sentenced to multiple life sentences. They now appeal.
II.
Shaheem argues that the district court erred when it failed properly to instruct the jury on the continuing criminal enterprise count. The federal CCE statute imposes penalties on “[a]ny person who engages in a continuing criminal enterprise.” 21 U.S.C. § 848(a). It further states that “a person is engaged in a continuing crimi
*353
nal enterprise if (1) he violates any provision of this subchapter or subchapter II of this chapter the punishment for which is a felony, and (2) such violation is a part of a
continuing
series
of [such] violations.”
21 U.S.C. § 848(c) (emphasis added). When the district court instructed the jury on the CCE count, it outlined the elements of the crime, and specifically instructed the jury that “[t]he phrase, [‘]A continuing series of violations, [’] means three or more violations of the federal narcotics laws, which are in some way related to one another.” J.A. 837. At the time, this court had held that the jury did not need to unanimously find each violation that comprised the series.
See United States v. Hall,
Shaheem claims that the district court erred when it failed to instruct the jury that it must be unanimous in its finding of each violation comprising the continuing series of violations. Specifically, Shaheem contends that under
Richardson v. United States,
As Shaheem concedes, “[tjrial counsel did not object to the jury instructions on Count 2, the CCE count,” Appellants’ Br. at 32, and, therefore, we review the district court’s failure to instruct the jury on unanimity in the CCE charge for plain error,
see id.
Under plain error review, we can only correct an error not objected to at trial if there is an “error,” that is “plain,” and that “affect[s] substantial rights.”
United States v. David,
We agree with Shaheem that, under
Richardson,
the district court erred when it failed to instruct the jury that it must unanimously find each violation that constitutes the continuing series of violations.
See Richardson,
We are likewise convinced that the error was plain error. In
Johnson v. United States,
*354
Even so, we are satisfied that this is not a case in which we should exercise our discretion to correct the error. At least fifteen of the alleged fifty-seven overt acts the Johnsons engaged in in support of their conspiracy to distribute cocaine were violations of narcotics laws by Shaheem alone. J.A. 98-111. And, the government adduced overwhelming evidence in the form of co-conspirators’ testimony and drugs found at Shaheem’s residence to show that Shaheem committed a multitude of violations of the federal narcotics laws. Even Shaheem concedes that at least two counts for which Shaheem was convicted could serve as predicate violations for the CCE conviction.
1
See
Appellants’ Reply & Opposition to Government’s Attempt to File Rule 28(j) Supplement, at 2. Shaheem’s narrow point is that we cannot technically know whether the jury agreed unanimously on the third violation from any of the fifteen overt acts. And, technically, this may be correct. But if ever there were a case in which we are confident that there is not a miscarriage of justice, it is this one, with a multitude of offenses, none of which the defendant seriously challenges.
2
Likewise, we are confident that the error did not seriously affect the fairness, integrity, or public reputation of judicial proceedings. Because the evidence adduced at trial was overwhelming, we are convinced that “based upon the record in its entirety, the proceedings against the accused resulted in a fair and reliable determination of guilt.”
United States v. Hastings,
III.
We now turn to the various other challenges the Johnsons make to their convictions and sentences.
A.
The Johnsons argue that the evidence presented at trial was insufficient to show that they were engaged in a single conspiracy to distribute cocaine. However, there was testimony that they traveled together to New York to obtain cocaine, J.A. 286-88; that they pooled their funds to purchase drugs from suppliers in New York, J.A. 215-17, 301-03; that together they purchased weapons from the same co-conspirator, J.A. 387-88; that Raheem took over territory to aid Shaheem in supplying cocaine to Maryland customers, J.A. 214-15; that they together shot and killed Bernard Franklin, someone whom they be *355 lieved had stolen drug money from Sha-heem, J.A. 194-95, 198-99, 227, 320, 343, 476, 702-05; and that together they hired someone to murder Richard Villa, whom they suspected wanted to steal from them, J.A. 520-21. Thus, we are confident that there was sufficient evidence in the record so that the jury could reasonably have found that they conspired together to distribute cocaine.
The Johnsons also claim that there was insufficient evidence to prove that they aided, abetted, and hired Eldon Brown to murder Richard Villa in violation of 18 U.S.C. § 1959. Under this section, the government had to prove that Brown killed Villa “as consideration for the receipt of, or as consideration for a promise or agreement to pay, anything of pecuniary value from an enterprise engaged in racketeering activity, or for the purpose of gaining entrance to or maintaining or increasing position in an enterprise engaged in racketeering activity.... ” 18 U.S.C. § 1959. According to the Johnsons, Brown had several reasons to murder Villa, none of which would have increased Brown’s position in the Johnsons’ racketeering activity. However, we are convinced that there was sufficient evidence in the record for the jury to find both that there was an agreement between the John-sons and Brown by which Brown would be paid from the Johnsons’ racketeering proceeds to murder Villa, and that Brown was attempting to increase or maintain his position in the Johnsons’ drug enterprise. Brown testified that he told the Johnsons that in order to “test” Villa, he told Villa that he was going to rob the Johnsons, and that Villa agreed to help. J.A. 516-18. He also testified that Shaheem told him that Shaheem and Raheem had work for Brown, and that they wanted him to murder “weak links” in the organization. J.A. 520 21. Finally, he testified that the John-sons agreed to pay Brown $150,000 for three murders, including the murder of Villa, J.A. 539, and that Shaheem gave Brown the handgun he used to murder Villa, J.A. 524.
B.
The Johnsons argue that the district court erred by not excluding hearsay statements allegedly made by Shawn Thomas regarding Raheem’s involvement in the murder of Antonio Stevens. Thomas was unavailable to testify at trial because Raheem murdered him before trial. Three witnesses testified that Thomas told them that he was with Raheem when Raheem murdered Stevens. 3 The district court appears to have admitted Thomas’ hearsay because, inter alia, 4 Raheem forfeited his hearsay objections, under Fed. R.Evid. 804(b)(6), by having caused the unavailability of Thomas as a witness. 5
The district court did not abuse its discretion in so holding. Under Rule 804(b)(6), “[a] statement offered against a party that has engaged or acquiesced in wrongdoing that was intended to, and did, procure the unavailability of the declarant as a witness” is admissible as an exception *356 to the rule against hearsay. Here, Ra-heem murdered Thomas at least in part to procure the unavailability of the only witness to his murder of Antonio Stevens.
Raheem argues that Thomas’ statements were not properly admitted under this rule for two reasons. First, Raheem claims that the district court should have conducted a hearing to confirm, by clear and convincing evidence, that Raheem did cause Thomas’ unavailability.
But see United States v. Emery,
Second, Raheem claims that even though Rule 804(b)(6) waives his right to object to the fact that Thomas is not available for cross-examination, the hearsay testimony must be “otherwise admissible as if Thomas were available to testify.” Appellants’ Br. at 48 (citing
United States v. Thevis,
C.
The Johnsons also claim that the district court erred when it denied their motion for severance, because they were actually involved in separate drug enterprises and were thus each prejudiced by *357 evidence presented against the other at trial. 6 For the reasons below, we conclude that the district court did not err when it denied the Johnsons’ motion for severance. First, the district court provided a cautionary instruction to the jury to prevent it from grouping all of the evidence against both defendants:
A separate crime is alleged against one or more of the defendants in each count of the indictment. Each alleged offense and any evidence pertaining to it should be considered separately by the jury-
The fact that you find one defendant guilty or not guilty of one of the offenses charged should not control your verdict as to any other offense charged against that defendant or any other defendant. You must give separate and individual consideration to each charge against each defendant.
J.A. 833-34;
see United States v. Porter,
D.
The Johnsons also claim that the district court erred when it did not permit them to present testimony related to the misconduct of a government witness, Rickey Piranti. The Johnsons wanted to question a witness about homicides allegedly committed by Piranti, which did not result in a conviction, in order to show that Pi-ranti -might have lied to avoid an indictment on those homicides. However, we are confident that the district court did not err when it refused to allow the Johnsons to question another witness about Piranti’s alleged homicides. Fed.R.Evid. 608(b) provides that,
[s]pecific instances of the conduct of a witness, for the purpose of attacking ... the witness’ credibility, other than conviction of crime ..., may not be proved by extrinsic evidence. They may, however, in the discretion of the court, if probative of truthfulness or untruthfulness, be inquired into on cross-examination of the witness ... concerning the witness’ character for truthfulness or untruthfulness.
Under Rule 608(b), the Johnsons could not question other witnesses about Piranti’s alleged homicides, but they were permitted to question Piranti, on cross-examination, about the alleged homicides. Additionally, we are confident that the district court did not err in refusing to allow the Johnsons to question a witness about Pi-ranti’s misconduct, because the district court found that such questioning would only confuse the jury on a tangential matter: “to allow introduction of this question before this witness ... is only going to inject confusion. It’s not relevant to any factor in terms of proof of this conspiracy. It doesn’t tend to prove or disprove any material fact in issue. Significant other evidence has already been presented and more will be presented, I’m sure, bearing on this witness’ credibility, and all this will do is promote confusion, it’s a collateral matter.” J.A. 712-13.
E.
Raheem contends that the trial court abused its discretion when it admit *358 ted testimony by a forensic expert, Sandra Wiersema, that compared tire tread impressions recovered from the scene of Ra-heem’s alleged killing of Antonio Stevens with tires recovered from Raheem’s car. At trial he objected to the testimony on the grounds that it was prejudicial and inflammatory because millions of the particular tires that made the tread marks were in circulation and it was impossible to know when the tread marks had been left at the scene of the crime. However, we conclude that the court did not err in finding that the testimony’s probative value outweighed any prejudicial value. The court properly weighed the factors relevant to the admissibility of the evidence— eyewitness statements that a car matching the description of Raheem’s car was seen leaving the scene of the murder; the timeliness in which the tire tread impressions were made after the murder; the fact that the expert could identify the particular make of the tire that left the marks; the fact that such tires were not manufactured until six months before the murder; and the likely number of vehicles with this type of tire — and ruled that the tire tread impressions were relevant and material. And, defense counsel vigorously cross-examined Wiersema, and made the point, in closing argument, that the tire tread impressions only matched the tread marks to Goodyear Eagle Aqua Tred tires, and did not necessarily match Raheem’s car to the impressions.
The Johnsons also argue that the district court erred by excluding their expert witness, Dr. Brownlee, from testifying regarding the cause and manner of death of two of the Johnsons’ alleged homicide victims, Shawn Thomas and Tracy Morgan. We cannot say that the district court erred by excluding Brownlee’s testimony, because the Johnsons did not disclose required information about the expert’s scheduled testimony to the government before trial. Under Fed.R.Crim.P. 16(b)(1)(C), the Johnsons were obligated to disclose to the government a written summary of the expert’s expected testimony, including the witness’ opinions, the bases and reasons therefor, and the witness’ qualifications. Although the Johnsons do claim that they turned over Brownlee’s resume to the government, there is nothing in the record that demonstrates that they complied with the other requirements of Rule 16, and the transcript indicates that defense counsel did not disclose the doctor’s opinion to the government, J.A. 799.
F.
Raheem argues that he could not be sentenced consecutively under both 18 U.S.C. § 1959(a)(1) and § 924(j) for the murders of four individuals, because the charge for .RICO murder, under section 1959, is a lesser included offense of the charge for committing a murder using a firearm during a drug trafficking offense, under section 924. 7
The district court did not err when it sentenced Raheem separately for both convictions. The same conduct can support convictions and sentencing under two different federal statutes as long as each statute requires proof of an element that the other does not.
See United States v. Terry,
Raheem argues that there was clear congressional intent that an individual not be separately punished for violating both provisions. He cites a House Report that is part of the legislative history of the Violent Crime Control and Law Enforcement Act of 1994, under which both statutory provisions were passed. It reads: “[i]n carrying out directions from the Congress, the U.S. Sentencing Commission shall ... avoid duplicative punishment for substantially the same offense.” H. Rep. No. 103-711, at 388. However, we do not read this direction to the Sentencing Commission to generally prohibit separate punishment for individual offenses, which have different elements, even when they relate to the same conduct. Accordingly, we cannot conclude that this general directive to the Sentencing Commission expresses clear congressional intent that an individual not be punished separately under section 1959 and section 924. Therefore, we conclude that the district court did not err when it permitted Raheem to be sentenced separately under each provision. 8
CONCLUSION
For the reasons stated herein, we affirm the Johnsons’ convictions on all counts.
AFFIRMED
Notes
. Shaheem also concedes, by implication, that certain alleged overt acts could qualify as violations. See Appellants’ Br. at 34 (“The government set forth over fifty overt acts in Count 1, many of which do not qualify as Violations'.... ”).
. Indeed, Shaheem's strategy throughout has been not to contest his involvement in drug trafficking. As illustrated by his counsel’s closing argument, the focus of his trial strategy was not to claim innocence of drug dealing, but rather to persuade the jury not to convict him on the murder charges and thus avoid the death penalty. Shaheem’s counsel told the jury in closing argument, "Nobody is fighting these drugs. There’s no way out on these drugs. You don't hear me talking about those drugs, do you?” Trial Transcript, Vol. XXII (Dec. 11, 1998), at 191. He made other statements such as “Shaheem Johnson sold drugs,” id. at 193, “That doesn't mean Sha-heem isn't guilty of drug dealing,” id. at 202, and Shaheem “[s]old drugs all his life,” id. at 215. Likewise, on appeal Shaheem has acknowledged that he was involved in drug trafficking. As we discuss in Section III.A., infra, the Johnsons (Shaheem and Raheem) argue that the evidence was insufficient to convict them on a single drug conspiracy because they were involved in multiple conspiracies. In the course of making this argument, they concede drug dealing on a large scale:
The [Johnsons] were both engaged in drug distribution activities, and they both knew about the other's operation, but those facts alone do not establish that they worked jointly in a common plan or scheme. The evidence revealed that appellants each had their own drug operations, with their own suppliers, distributors, and couriers. On occasion, they would purchase large quantities of narcotics together.
Appellants' Br. at 25.
. The witnesses who recounted details of the murder, as told to them by Thomas, were Jeremy Williams, J.A. 434-42; Keah Lorrick, J.A. 583-97; and Larry Jackson, J.A. 633-48, 801-04.
. The district court also admitted the hearsay statements as statements against Thomas' penal interest, under Fed.R.Evid. 804(b)(3), as statements by a coconspirator made in furtherance of the conspiracy, under Fed.R.Evid. 801(d)(2)(E), and as otherwise reliable and probative statements under Fed.R.Evid. 807, the residual exception to the hearsay rule. However, because we hold that the district court did not abuse its discretion by admitting the statements under Fed.R.Evid. 804(b)(6), we decline to review the court's other grounds for admitting the testimony.
.In its summation of its ruling on the admissibility of the Thomas hearsay, the district court did not specifically cite Rule 804(b)(6) as a ground for its decision to admit the testimony. However, the government argued that Rule 804(b)(6) was the primary ground for admissibility, J.A. 411-27, and the court discussed the rule and its application to Ra-heem's case before its summation, J.A. 427.
. The Johnsons also argue that because they are identical twins, the jury could easily have been confused, and they should have been tried separately. However, they cite nothing in the record to indicate that witnesses confused them or that they were not separately identified. Thus, we are not convinced that they were prejudiced by being tried together merely because they are twins.
. To prove a violation of section 1959(a)(1), the government must show that there was (1) an enterprise engaged in racketeering activity, (2) murder or aiding and abetting another person in murdering, and (3) murder undertaken for the purpose of gaining entrance into or maintaining the defendant's position in the enterprise, or in exchange for anything of pecuniary value. See 18 U.S.C. § 1959(a)(1).
To prove a violation of section 924(j), the government must show that there was (1) a drug trafficking crime committed, (2) the use of a firearm during the commission of the trafficking crime, and (3) malice aforethought in causing the death of the victim in relation to the commission of the crime. See 18 U.S.C. § 924Q).
. We also reject Raheem’s claim that his trial counsel was ineffective because the record does not support this claim. And, we have reviewed the claims made by Shaheem in his motion for leave to file a pro se supplemental brief, and finding those claims to be meritless, we deny the motion.
