Moore, Hays and Feinberg, Circuit Judges.
In August 1970, a one-count indictment was filed in the United States District Court for the Eastern District of New York, charging 21 defendants with conspiracy to violate the narcotics laws. 21 U.S.C. §§ 173, 174 (now 21 U.S.C. §§ 952, 960). The indictment also identified five co-conspirators who were not listed as defendants.*fn1 Eleven of those charged in the indictment were tried in 1971. Ten were found guilty, and this court affirmed their convictions. United States v. Vega, 458 F.2d 1234 (2d Cir. 1972). In June 1972, the four defendants involved in this appeal -- George Nathan, Robert Brown, Clarence Nash, and Rene Boulier -- were brought to trial on the same indictment before Chief Judge Jacob Mishler and a jury.*fn2
The Government's case rested principally on the testimony of two co-conspirators. The jury could properly have found that the four appellants had worked for or dealt with a group headed by one Jesus Torrado, one of the 21 indicted and now a fugitive, who was based in New York City. Heroin and cocaine were imported into the country through Miami, and purchased there by Torrado's men. They then brought the drugs to New York City and made sales to buyers in the city and elsewhere. Three of the four appellants were identified by Government witnesses as having purchased substantial quantities of narcotics from Torrado, apparently on a fairly regular basis. The fourth appellant -- Rene Boulier -- was described as a member of Torrado's organization, performing such tasks as preparation and delivery of heroin and cocaine. All four appellants were convicted, and they now appeal on divers grounds.*fn3
I. Double Jeopardy and a Prosecutorial Promise
The most substantial argument raised on appeal is based upon legal proceedings that took place in the United States District Court for the Southern District of Florida. Appellant Boulier was indicted there with 12 others on October 14, 1969 for his role in a drug importation and distribution conspiracy. Seven or eight of the 36 participants named in the Florida indictment were also identified as co-conspirators in the instant indictment in New York, which was filed ten months later. On December 20, 1971, a superseding information was filed in the Florida court, charging that Boulier, together with three named individuals (two of whom had also been named in the New York indictment), and others unknown, had conspired to violate 26 U.S.C. § 4704(a) by purchasing and selling heroin not in or from the original stamped package. Boulier pleaded guilty to the information, and the original Florida indictment was dismissed.
Boulier asserts that his guilty plea to the federal information in Florida precluded his conviction under the New York indictment by operation of the Double Jeopardy Clause. Judge Mishler rejected this claim, concluding that the conspiracy alleged in the information was separate from and not merely one component of the conspiracy described in the New York indictment.
We need not decide whether the two conspiracies charged were identical in fact.*fn4 It is sufficient to observe that the two convictions were based upon different statutory violations; the second, unlike the first, required a showing of defendant's knowledge of illegal importation.*fn5 That a defendant may be punished for multiple violations of the narcotics laws arising from a single transaction is well settled, see Gore v. United States, 357 U.S. 386, 78 S. Ct. 1280, 2 L. Ed. 2d 1405 (1957);*fn6 and we are not aware of any constitutional requirement that all such violations must be tried together. See, e.g., United States v. Jones, 334 F.2d 809, 811 (7th Cir. 1964), cert. denied, 379 U.S. 993, 85 S. Ct. 707, 13 L. Ed. 2d 613 (1965).*fn7
Boulier advances another argument based upon the Florida proceedings. The supersession of the original indictment by the information and Boulier's guilty plea were the outgrowth of an agreement between the federal prosecutor in the Southern District of Florida and Boulier's attorney. Under this agreement, Boulier was to provide federal authorities with information concerning the sale and distribution of narcotics in the United States and Latin America. In exchange, the indictment would be dismissed, Boulier would plead guilty to the lesser charge in the information,*fn8 and would receive probation. In addition, the United States Attorney in that district apparently assured Boulier that the Government would agree to the dismissal of the indictment pending in the Eastern District of New York. Based upon the latter promise, which was obviously never carried out, Boulier urges that the Government should be estopped from prosecuting him in this proceeding. We put to one side such questions as the authority of one United States Attorney to bind another or the proper remedy for a defendant who has been deceived by such a promise. The record indicates that Boulier failed to carry out his part of the bargain by refusing to disclose the promised information and hence is in no position to invoke the agreement now.*fn9
II. Evidence of Later Crimes
All four appellants challenge the introduction of evidence of a series of post-conspiracy transactions and, in the case of George Nathan, two arrests for possession of cocaine. As to the former argument, evidence of a conspirator's post-conspiracy activity is admissible if probative of the existence of a conspiracy or the participation of the alleged conspirator. Lutwak v. United States, 344 U.S. 604, 617-619, 73 S. Ct. 481, 97 L. Ed. 593 (1953); United States v. Bennett, 409 F.2d 888, 893 (2d Cir.), cert. denied, 396 U.S. 852, 90 S. Ct. 113, 117, 24 L. Ed. 2d 101 (1969).*fn10 Hence the prosecution could properly introduce evidence that appellants had, on a number of occasions after August 1968, engaged in drug transactions and other activities that usually accompany such criminal conduct.*fn11
Appellant George Nathan specifically complains about the Government's use of rebuttal testimony by two police officers, who described the circumstances of Nathan's two post-conspiracy arrests on drug charges. Neither arrest led to a conviction, and Nathan asserts that they should not have been used against him by means of extrinsic proof. However, appellant opened the door to such an inquiry through his own testimony. On direct examination he declared that he did not use cocaine or heroin and had never engaged in the transportation or distribution of any narcotic drug; on cross-examination, while admitting the two arrests, he denied that he had possessed narcotics at the time of his second arrest or that he had known of the presence of drugs in his apartment at his first arrest. The testimony of the officers suggested the strong likelihood that Nathan had in fact been knowingly in possession of cocaine on both occasions, and the trial judge could therefore, in his discretion, admit such testimony to disprove Nathan's assertions. See Walder v. United States, 347 U.S. 62, 74 S. Ct. 354, 98 L. Ed. 503 (1954); United States v. Keilly, 445 F.2d 1285, 1289 (2d Cir. 1971), cert. denied, 406 U.S. 962, 92 S. Ct. 2064, 32 L. Ed. 2d 350 (1972) (limiting United States v. Glasser, 443 F.2d 994 (2d Cir.), cert. denied, 404 U.S. 854, 92 S. Ct. 96, 30 L. Ed. 2d 95 (1971)).
III. Brown's Business Card and His 1945 Arrest
At trial, the Government introduced into evidence a business card of appellant Robert Brown, who owned a record store. Brown challenges the admission of the card as unwarrantedly prejudicial.*fn12 The card in question had been taken from Jesus Torrado's apartment when he was arrested. The relevance of the card is that it served as circumstantial evidence of Brown's involvement with Torrado and the conspiracy. Used for this purpose, introduction of the card was proper. See United States v. Canieso, 470 F.2d 1224, 1232 (2d ...