Accomplice witnesses with immunity should be required to plead guilty to some of the charges against them, with sentencing delayed until after the testimony to provide incentive for cooperation and truthfulness. Such sentences are less offensive to juries than complete immunity from prosecution in return for testimony. Immunity agreements should explain what will happen if the witness lies. Such sanctions will help convince the jury that the witness has every reason to tell the truth. Independent proof, however, is an essential aspect of showing that an accomplice is telling the truth. The most effective corroborating evidence is the testimony of an unbiased eyewitness or an admission by the defendant. Admissions by the defendant are more common than eyewitness evidence in criminal conspiracy cases. Defendant admissions can come from tape recordings from consensual or court authorized eavesdropping or through the testimony of a second accomplice. The prosecutor should make every effort to diffuse the impact of using an admitted criminal as a primary witness. This fact should be acknowledged to the jury in the opening statement. The prosecutor should emphasize the necessity of such testimony in criminal conspiracy cases, the 'insider' knowledge possessed by the witness, and the incentives in the immunity agreement that prompt the witness to tell the truth. The prosecutor should prepare the witness to deal with defense efforts to undermine his credibility under cross-examination.