Alex Debango was convicted in a jury trial of conspiracy to distribute heroin, in violation of 21 U.S.C. § 846 (1982), and of unlawful distribution of heroin, in violation of 21 U.S.C. § 841(a) (1982). Because we find no error, we affirm appellant’s conviction.
I. Background
Appellant, a Washington cab driver, claims that he was approaсhed by Tom Robinson, a government informant, and asked to assist in uncovering narcotics dealers under the “Crime Solvers Program.” Appellant claims that he was promised $1,000 for his assistance in uncovering drug dealers. Therefore, when he was introduced to Tombora Hofongo, who told appellant that he was selling heroin, appellant passed the information on to Robinson. Robinson then introduced appellant to Detective Dwight Rawls.
The government claims that Robinson introduced Detective Rawls to appellant as a buyer interested in purchasing a quantity of heroin. According to Detective Rawls, appellant assured Rawls that appellant had the right connections and could facilitate delivery of the heroin. Appellant and Rawls then arranged to meet with a man, later identified as co-defendant Tombora Hofоngo, who would provide the heroin. At that time appellant provided Rawls with, a 78-milligram sample of 88 percent pure heroin.
The next day Rawls, appellant, and Robinson met with Hofongo to discuss the purchase of a large quantity of heroin. The sale was not actually consummаted until several weeks later, on August 13, 1984, when appellant was not present. At that time Detective Rawls met with Hofongo and co-defendant Godson Ezebuiro, who sold Rawls a one-ounce package of heroin for $5,500 in marked bills. The following day the same group reconvened tо discuss another sale. After Ezebuiro gave Rawls more heroin, Rawls signaled other agents and the group was arrested. A search of Ezebuiro’s apartment uncovered more heroin, plastic bags, cutting agents, and a triple-beam scale. In addition, Chizoba Obasi, who was living there, was аrrested. The marked bills were found in Ezebuiro's apartment as well as in Hofongo’s apartment.
The government filed an indictment charging appellant, along with co-defendants Tombora Hofongo, Godson Ezebuiro, Chizoba Obasi, and Uchenna Ezebuiro, with conspiracy to distribute heroin, unlawful distribution of heroin, and unlawful possession of heroin with intent to distribute. Appellant was named only in the conspiracy count and in one count of possession with intent to distribute. Appellant made pretrial motions for disclosure of the informant's identity and for severance of the defendаnts. The court denied both motions and dismissed the charges against Uchenna Ezebuiro. Tombora Hofongo subsequently pleaded guilty to conspiracy and to one other charge. Appellant and Godson Eze-buiro were convicted and Chizoba Obasi was acquitted of all chargеs. Godson Eze-buiro has not appealed his conviction.
II. Appellant’s Pretrial Motions and the Jury Instructions
Appellant first challenges his conviction on the ground that the District Court improperly denied his motion to sever the defendants. Because the evidence in this case establishes, at best, merely a “one-time” conspiracy to distribute only the small “sample” amount of heroin between Hofongo and appellant, appellant argues, failure of the court to sever defendants Ezebuiro and Obasi was error. Appellant argues that once defendant Hofongo pleaded guilty, no evidеnce linked appellant with his co-defendants. We reject this argument. A District Court clearly has discretion whether to sever defendants under *84 Federal Rule of Criminal Procedure 14, and appellant has simply failed to carry his burden of demonstrating ah abuse of that discretion. The government’s evidence was sufficient to allow the jury to conclude that appellant played a key role in the larger conspiracy as the “flag man” who screened potential customers.
Appellant next challenges his conviction on the ground that the District Court erred in failing to grant his motion for disclosure of the government informant’s identity and location. Appellant argues that the informant would have been a material witness and would have been helpful to appellant’s defense. Therefore, appellant argues, failure to disclosе the informant’s current address constituted reversible error. We disagree.
As an initial matter, appellant never moved for disclosure of the informant’s location and therefore cannot now complain on that score. See Transcript of October 17, 1984 Status Call Hearing at 12-14. Moreover, trial counsel conceded that the government had confirmed Robinsоn’s identity with the Drug Enforcement Agency and disclosed it to defendant. Id. at 12-13. Thus, because appellant failed to seek disclosure of Robinson’s location and because he received a confirmation of Robinson’s identity, we find no basis for appellant’s complaint.
Appellant further argues that the District Court erred in its jury instructions. First, he argues, the court failed to give a multiple-conspiracy instruction, informing the jury that the second, larger sale of heroin could be considered a separate and distinct conspiracy unrelated to appellant. Second, he argues, the District Court erred in failing to give a “missing informant instruction” to the jury. Such an instruction informs the jury that when a party fails to utilize a witness peculiarly within his power to produce and whose testimony would elucidate the transaction, the jury may infer that the witness’ testimony would have been unfavorable.
See Graves v. United States,
The Federal Rules of Criminal Procedure, however, expressly bar a party from contesting the jury instructions given by the District Court unless he objects below or the error constitutes plain error. Fed.R.Crim.P. 30, 52(b).
See also United States v. Campbell,
Appellant in this case did not object to the instructions below and consequently must demonstrate plain error. We find that the failure to give a multiple-conspiracy instruction was not plain error, given that the government’s evidence was clearly sufficient to support a finding that appellant and his co-defendants were engaged in a single overall conspiracy. Further, appellant failed to lay the foundation for a missing informant instruction by demonstrating that the informant was peculiarly within the government’s control. Absent such a foundation, a missing informant instruction cannot properly be given.
See Brown v. United States,
III. Ineffective Assistance of Counsel
Appellant’s most credible claim is that he was denied effective assistance of counsel in violation of the Sixth Amendment.
1
In
Strickland v. Washington,
Appellant claims that counsel’s performance did amount to ineffective assistance of counsel because: (1) counsel failed to interview or to call two witnesses, one of whom could have testified that he overheard Robinson, the informant, ask aрpellant to participate in the “Crime Solvers Program,” (2) counsel failed to request certain jury instructions, 2 (3) counsel failed to locate Robinson, and (4) counsel slept through large portions of the trial.
Counsel’s failure to interview the proposed witnesses is troublesome. Had trial counsel interviewed the witnesses, his decision not to call them might be protected from an ineffective assistance claim as a tactical litigation decision. The complete failure to investigate potentially corroborating witnesses, however, can hardly be considered a tactical decision. As the Supreme Court noted in
Strickland,
“[C]oun-sel has a duty to make reasonable investigations or to make a reasonable decision that makes particular investigations unnecessary.”
Even if counsel’s performance fell below рrevailing professional norms, however,
Strickland
requires that a defendant establish prejudice.
To put the prejudice issue in context, we note that the evidence against aрpellant was compelling. Moreover, because the District Court judge was able to hear appellant’s original testimony and weigh his credibility, he was in the best position to evaluate whether appellant had been prejudiced by counsel’s failure to interview Mills.
*86 Appеllant also argues that he was denied effective assistance of counsel because his attorney failed to locate and interview Robinson, the informant. Again, however, we find that appellant failed to carry his burden of demonstrating prejudice under the Strickland analysis. Because appellant failed to introduce evidence in the District Court, in the new trial motion, of what Robinson would have said had trial counsel located him, the record simply fails to support his claim that he was prejudiced by counsel’s failure to locate Robinson. 4
Finally, apрellant argues that he was denied effective assistance of counsel because his lawyer slept through much of the trial. Whatever the merits of this claim,
see Javor v. United States,
Thus, because we do not think the District Court’s finding on the Mills affidavit was error, and because there is no evidence of what Robinson would have said had he been interviewed or evidence to support appellant’s charge of counsel’s sleeping at trial, there is no basis for a finding of prejudice. We note that when counsel changes prior to appeal and when there is still a reasonable opportunity to challenge a conviction in the District Court, a criminal defendant bears the usual obligation to raisе issues and introduce evidence in the trial court in order to preserve his claims on appeal. 6
For the foregoing reasons, we reject appellant’s challenges to his conviction.
Affirmed.
Notes
. Appellant’s counsel on appeal replaced appellant’s trial counsel only after the case had been appealed to this court. Appellant was sequentially represented by three different lawyers during and immediately after his trial. The lawyer who represented appellant after the conclusion of the trial and bеfore the appeal supported appellant’s motion for a new trial by arguing, among other things, that appellant had been denied the effective assistance of counsel during the trial.
. Because the proposed jury instructions would have been problematiс even had trial counsel proposed them, failure of trial counsel to request the instructions did not constitute a violation of the prevailing professional norms.
.
See also Nealy v. Cabana,
. The third proposed witness, David Dawson, is the cab company dispatcher. Dawson would only have testified that appellant had received several telephone calls from someone named "Tom.” See Affidavit of David A. Dawson, Supplemental Reсord on Appeal at 15. Thus counsel’s failure to interview Dawson is unlikely to have affected the outcome of the case.
. With his appellate brief appellant submitted two affidavits of courtroom spectators who stated that appellant’s counsel apрeared to be asleep during much of the trial. Clearly, however, this court cannot evaluate this evidence presented for the first time on appeal.
United States v. Hart,
. We therefore decline to remand the case to allow appellant to substantiate his contentions concerning Robinson and the sleeping charge.
United States v. Hinton,
