concurring:
I see no justification and considerable danger in impeaching a defendant’s credibility with a prior conviction for the same type of offense as the one on trial when the prosecutor already has available for impeachment another conviction for a different type of offense. In Washington’s trial for bank robbery, it would have been entirely appropriate to impeach his credibility, if he had testified, with his prior conviction for larceny. Not content to rely on that substantial attack on credibility, the prosecutor offered and the District Judge indicated a willingness to accept evidence of a prior bank robbery conviction, ostensibly only for purposes of impeachment.
Once credibility is impeached by a prior felony conviction, the incremental probative force of a second conviction is minimal. Yet the prejudicial effect is substantial when the second conviction is for the same type of offense as the pending charge. We expect a great deal of juries when we instruct them to consider any conviction only for impeachment of credibility and not as evidence of a propensity to commit crime. However dubious our faith in the jury’s ability to make that distinction in most cases, there is really no excuse for pushing the matter to the breaking point by admitting a prior conviction for the same type of offense being tried once credibility has already been adequately impeached by another conviction. A juror might well wonder what purpose the prior bank robbery conviction should serve except as evidence that the defendant robs banks; the juror already would know from the larceny conviction that the defendant’s veracity is subject to challenge.
We have previously upheld a District Judge’s exercise of discretion in somewhat similar circumstances, see United States v. Oliver, 626 F.2d 254, 264 (2d Cir.1980); see also United States v. Oaxaca, 569 F.2d 518, 526-27 (9th Cir.), cert. denied, 439 U.S. 926, 99 S.Ct. 310, 58 L.Ed.2d 319 (1978), and thereby consigned the matter to the virtually unreviewable discretion of the trial judge under Rules 609(a)(1) and 403 of the Federal Rules of Evidence. Especially in this case, where the defendant made no adequate offer of proof as to the substance of his testimony,1 I agree that no basis has been shown to reverse the conviction.2 *108However, the issue is well worth the careful attention of trial judges, whose exercise of discretion in considering a second and similar prior conviction ought to be guided by extreme caution.
. An offer of proof has been thought useful to assist the trial judge in exercising discretion in giving an advance ruling as to whether a prior conviction will be admitted for impeachment in the event the defendant testifies. See United States v. Costa, 425 F.2d 950, 954 (2d Cir.1969), cert. denied, 398 U.S. 938, 90 S.Ct. 1843, 26 L.Ed.2d 272 (1970); United States v. Cacchillo, 416 F.2d 231, 234 (2d Cir.1969); Gordon v. United States, 383 F.2d 936, 940 (D.C.Cir.1967), cert. denied, 390 U.S. 1029, 88 S.Ct. 1421, 20 L.Ed.2d 287 (1968). One might think that the exercise of discretion under Rules 609(a)(1) and 403 ought to be confined to weighing the probative value of the prior conviction as impeachment of credibility versus its prejudicial value as evidence of bad character. Under this view, the significance of the testimony the defendant would have given but did not because of an adverse evidentiary ruling would be weighed only by the reviewing court in deciding whether the ruling to permit impeachment, if erroneous, was sufficiently prejudicial to affect a substantive right of the defendant within the meaning of Fed.R.Evid. 103(a). See United States v. Cook, 608 F.2d 1175, 1193, 1196-97 (9th Cir. 1979) (in banc) (Hufstedler, J., with whom Ely, J., joins, dissenting in part), cert. denied, 444 U.S. 1034, 100 S.Ct. 706, 62 L.Ed.2d 670 (1980).
. I have some doubt whether the denial of a motion to exclude impeaching convictions is reviewable in a case such as this where the defendant does not testify. But, in anticipation of the Supreme Court’s resolution of that issue, Luce v. United States, — U.S. -, 104 S.Ct. 1677, 80 L.Ed.2d 152 (1984) (granting writ of certiorari in United States v. Luce, 713 F.2d 1236 (6th Cir.1983)), I accept the prior practice of our Circuit. United States v. Vanderbosch, 610 F.2d *10895 (2d Cir.1979); United States v. Hayes, 553 F.2d 824 (2d Cir.), cert. denied, 434 U.S. 867, 98 S.Ct. 204, 54 L.Ed.2d 143 (1977).