Manuel Jiminez appeals from his December 6, 1978, conviction of heroin distribution in violation of 21 U.S.C. § 841(a)(1) (1976). Appellant Jiminez alleges that reversible error occurred in his jury trial when government counsel cross-examined appellant about his possession of cocaine in unrelated circumstances occurring more than a year after the offense charged. Finding this uncorroborated and prejudicial accusation of an extrinsic offense to be contravention of Fed.R.Evid. 404(b), we reverse and remand for retrial. Additionally, we caution government counsel on retrial to comply with Fed.R.Evid. 612 and the Jencks Act, 18 U.S.C. § 3500 (1976), in any use of police surveillance reports to refresh witnesses' memories.

Appellant Jiminez has never denied consummating the illegal transaction alleged in his indictment. At trial he acknowledged that on October 21, 1977, he sold one ounce of heroin to Pedro Hernandez, a federal Drug Enforcement Administration agent who was working undercover. However, appellant asserted an entrapment defense. He claimed that agent Hernandez and informant Cho Chi Escomellia persuaded him to locate and sell the contraband for money to get appellant's older brother out of jail.

In his efforts to establish his asserted defense, appellant testified on direct examination that until the alleged heroin sale, he had never trafficked in drugs. On cross-examination, government counsel sought to rebut appellant's professed prior innocence and to reveal a predisposition on appellant's part to make such a sale.

Pursuant to that goal the prosecutor questioned appellant about his purported cocaine possession a year later at his arrest on the heroin charge.1 Appellant now challenges under Fed.R.Evid. 404(b)2 the admissibility of that inquiry. To meet the requirements of Fed.R.Evid. 404(b), such extrinsic offense evidence must clear both admissibility hurdles set up in United States v. Beechum, 582 F.2d 898, 911 (5th Cir. 1978), Cert. denied, 440 U.S. 920, 99 S. Ct. 1244, 59 L. Ed. 2d 472 (1979). "First, it must be determined that the extrinsic offense evidence is relevant to an issue other than the defendant's character. Second, the evidence must possess probative value that is not substantially outweighed by its undue prejudice and must meet the other requirements of rule 403."3 Id.

The predicate to relevance of an extrinsic offense is proof that the defendant actually committed the offense. Id. at 912-13. The government need only produce evidence which would withstand a directed verdict on the extrinsic offense. United States v. Byers, 600 F.2d 1130, 1132 (5th Cir. 1979); United States v. Beechum, 582 F.2d at 913. In this case, the extrinsic offense evidence loses the race toward admissibility before even reaching the starting mark. Appellant Jiminez steadfastly denied any knowledge of the cocaine's presence in his room prior to its discovery, and the record suggests that appellant may even have shared with another the room where the cocaine was found. Moreover, the record reveals no testimony corroborative of the prosecutor's accusations, nor even any indication that appellant had ever been formally charged with cocaine possession. Under these circumstances, no reasonable jury could have found appellant guilty of the alleged cocaine possession. Consequently, the extrinsic offense evidence failed to clear the Beechum probity hurdle and should not have been admitted.

Even had the extrinsic offense evidence passed the first test, however, it would have faltered at the second obstacle. A year had lapsed between the heroin deal and appellant's alleged cocaine possession. Although we do not suggest that subsequent extrinsic offense evidence could never be admitted under rule 404(b), it certainly bears substantially less on predisposition than would a prior extrinsic offense. United States v. Daniels, 572 F.2d 535, 538-39 (5th Cir. 1978). We find that the expiration of the considerable length of time in this case depleted the extrinsic offense of any relevance which could have outweighed the peril of jury prejudice. See United States v. Hitsman, 604 F.2d 443, 448 (5th Cir. 1979); United States v. Byers, 600 F.2d at 1133; United States v. Daniels, 572 F.2d at 538-39.

Additionally, the record fails to reveal any limiting jury instructions which might have ameliorated the prejudicial nature of the cocaine possession evidence. While sustaining defense counsel's objection to the extrinsic offense evidence, the trial judge stated only, "I will so instruct the jury."4 The jury charge at the close of the evidence contained no more expository instructions. Although the lack of curative instructions does not invariably mandate mistrial, a judge should carefully limit the use of extrinsic offense evidence whenever any possibility of undue prejudice exists. United States v. Contreras, 602 F.2d 1237, 1240 (5th Cir. 1979); United States v. Aleman, 592 F.2d 881, 886 (5th Cir. 1979); United States v. Underwood, 588 F.2d 1073, 1076-77 (5th Cir. 1979); United States v. Jackson, 588 F.2d 1046, 1056 (5th Cir.), Cert. denied, --- U.S. ----, 99 S. Ct. 2882, 61 L. Ed. 2d 310 (1979).

Even the most careful of instructions, however, would not have sufficiently limited the prejudicial nature of the extrinsic offense evidence in this case. For its limited probative value, evidence of the subsequent offense posed too great a risk of improper jury decision on the basis of appellant's character or propensity to commit drug-related offenses.5 Because this extrinsic offense evidence can never overcome the obstacle of impermissible prejudice, it will not be admissible at appellant's retrial even if government counsel could produce corroborative evidence which would satisfy the first level of the Beechum test.

Appellant contends that reversible error occurred when the prosecutor showed to Leonard Alphin, a surveillance agent and government witness, a police surveillance report from which the agent admittedly had already refreshed his memory. Although other grounds have already dictated reversal, we nonetheless review the claim because the surveillance report may well be used at appellant's retrial. See United States v. Daniels, 572 F.2d at 539.

We need not determine whether the surveillance report was subject to the Jencks Act, 18 U.S.C. § 3500 (1976), to answer appellant's claims. If the report was not Jencks Act material, it fell under Fed.R.Evid. 612.6 Under rule 612, the prosecutor should have prefaced the agent's testimony with a showing that the witness needed to review the report to revive his recollection. See J. H. Rutter Rex Manufacturing Co. v. NLRB, 473 F.2d 223, 239 (5th Cir.), Cert. denied, 414 U.S. 822, 94 S. Ct. 120, 38 L. Ed. 2d 55 (1973); Thompson v. United States, 342 F.2d 137, 139 (5th Cir.), Cert. denied, 381 U.S. 926, 85 S. Ct. 1560, 14 L. Ed. 2d 685 (1965); NLRB v. Hudson Pulp & Paper Corp., 273 F.2d 660, 665 (5th Cir. 1960); III Wigmore § 758 n. 3 (Chadbourn rev. 1970). Because the agent's testimony was not prefaced with the requisite showing of need, his testimony should not have been admitted unless it came within the Jencks Act exception to rule 612. As Jencks material, the surveillance report could have been used by the agent to refresh his memory without the prior showing of need, because the Jencks Act bars disclosure of a government witness' reports or statements until the witness has testified on direct examination. 18 U.S.C. § 3500(a).

Although it delays disclosure of the witness' report or statement until the conclusion of the witness' direct examination, the Jencks Act also mandates disclosure at that time, upon the defendant's motion. Id. Appellant claims that the prosecutor did not surrender the surveillance report at the appropriate time, but waited until the middle of defense counsel's cross-examination of the surveillance agent before proffering the report. The record does not support his assertion. Rather, it indicates that defense counsel requested and received the surveillance report at the conclusion of another agent's testimony much earlier in the trial. Record at 86.

Without any greater merit is appellant's argument that the surveillance report was somehow "constructively" made part of the evidence in contravention of Fed.R.Evid. 803(8)(B).7 The record gives no indication that the report was ever admitted, constructively or otherwise.

Because the extrinsic offense evidence in this case violated Fed.R.Evid. 404(b), appellant's conviction is REVERSED and REMANDED. Additionally, we caution government counsel on retrial to use the police surveillance reports in careful compliance with Fed.R.Evid. 612 and the Jencks Act, 18 U.S.C. § 3500 (1976).

REVERSED AND REMANDED.