The Set-Up

D is charged with ten counts of possession of U.S. Treasury checks stolen from the mails in violation of 18 U.S.C. §1708. The prosecution's evidence indicates that postal inspector Wilson was approached by an informant who arranged a "check buy" from D. Wilson arranged to meet the informant and D at a restaurant. After preliminary discussions D left briefly, returning with ten U.S. Treasury checks made out to various payees. Five of the checks had forged endorsements, and five were unendorsed. Wilson offered to pay D 25 percent of the face value of the checks. D accepted this offer. Wilson then left, presumably to obtain the cash, and government agents arrested D, feigning the arrest of Wilson and the informant.

At trial, D acknowledges that he sold Treasury checks to Wilson but claims that his arrest was a product of entrapment. He asserts that he had met the informant, "Jimmy," at the home of a friend and that Jimmy asked him if he "did checks" or "could get checks." D testifies that he told Jimmy that he was not interested but that Jimmy was not satisfied with this initial rebuff and continued to pursue him both by visiting and telephoning him on numerous occasions. D asserts that he obtained checks solely in order to pass them on to Jimmy and satisfy him. D also testifies that when Jimmy told him about the proposed check buy, D protested but finally agreed to go ahead with the deal only under duress.

D seeks to introduce the testimony of his co-defendant's mother that she received several telephone calls from someone named "Jimmy" who said that he was looking for D.The proposed witness was not acquainted with the informant and there was no evidence offered that she could recognize his voice at the time. Is the evidence admissible?

Would it make a difference if the witness testified that although she did not recognize Jimmy's voice at the time, after hearing the informant testify at trial she recognized the voice on the telephone as belonging to him?