(dissenting).
For some time, I have expressed concern over the almost unbroken line of cases in this Circuit which have permitted the use of evidence of prior bad acts to improperly influence convictions. See United States v. Simon, 842 F.2d 552, 555 (1st Cir.1988) (Torruella, J., concurring), and the cases cited therein. In view of the indiscriminate broadening of this pervasive trend, I believe that there is an ever-present cause for alarm.
Federal Rule of Evidence 404(b)1 clearly limits the use of prior bad act evidence to carefully circumscribed situations. Unfortunately, we have made it increasingly facile for the exceptions to become the rule. As I previously pointed out,
The prohibition against the introduction of “[ejvidence of other crimes ... to prove the character of a person in order to show action in conformity therewith,” mandated by Fed.R.Evid. 404(b) as well as due process, Lovely v. United States, 169 F.2d 386, 389 (4th Cir.1948), ... has become the exception rather than the rule, a classical case of the tail wagging the dog. Almost any excuse or farfetched theory is made to fit within that Rule’s truly exceptional language, i.e., that such evidence is admissible only as “proof of motive, opportunity, intent, preparation, plan, knowledge, identity, or absence of mistake or accident.” See Fed.R.Evid. 404(b).
United States v. Simon, 842 F.2d at 556 (Torruella, J., concurring). The majority’s decision in the present case illustrates this unfortunate point.
*142Over defendant’s objection, evidence was introduced that he previously pled guilty to two charges of possessing cocaine and marijuana in 1985. That evidence should have been excluded from this trial and it was an error not to do so. Although Fed.R.Evid. 404(b) permits the use of evidence of other crimes, not to prove the character of a person, but as “proof of motive, opportunity, intent, preparation, plan, knowledge, identity, or absence of mistake or accident,” Fed.R.Evid. 404(b), these exceptions are tempered by Fed.R.Evid. 403. See United States v. Rubio-Estrada, 857 F.2d 845, 847 (1st Cir.1988). Rule 403 permits admission of such evidence unless its probative value is “substantially outweighed by the danger of unfair prejudice, confusion of the issues, or misleading the jury.” Fed.R.Evid. 403. See also Rubio-Estrada, 857 F.2d at 847. There is no question that the evidence of the prior convictions did all these three things.
The asserted basis for admission of Ferrer’s two prior convictions for possession of controlled substances was to permit the jury to infer that the appellant was knowledgeable about drug trafficking and that he committed the crime of possession of narcotics with intent to distribute in a manner inconsistent with mistake or accident. The district court held that the evidence was admissible, even after deeming it “quite prejudicial,” because it concluded that the appellant raised the issues of intent and knowledge by pleading not guilty. This is a remarkable conclusion. I fail to see how this type of evidence will ever be excluded merely because a defendant pleads not guilty — which is to say, every time a criminal trial takes place. If that is all that is needed to trigger the admission of such evidence, it will for all intents and purposes always be admissible.
The majority’s suggestion that without the prior act evidence a reasonable juror might have had reasonable doubt about Ferrer’s guilt, and that the prior act evidence would help to overcome that doubt, illustrates exactly the reason why the evidence should have been excluded: it is unfairly prejudicial because it relieves the government of its burden of proving beyond a reasonable doubt, the essential elements of the current crime. The inference that the Rule 403 balance of “probative weight” against “prejudicial effects” weighs on the side of admissibility solely because it may help the government’s case is preposterous. Most of the evidence that is routinely excluded from admission, including extorted confessions, is undoubtedly “helpful” to a weak government case. Such reasoning flies in the face of the very wording of the Rule, and renders it virtually meaningless. It is bootstrap logic, which should not be the basis for a conviction.
As far as I can discern, whether Appellant committed the charged crime accidently or mistakenly was never an issue in the case and is not raised merely by pleading not guilty. Ferrer never argued lack of knowledge or intent. The fact that he testified what amounts to “mere presence” before the grand jury is totally immaterial. The Fifth Amendment prevents a trial court from requiring a criminal defendant to disclose his defense until trial, unless the situation comes within one of the recognized exceptions to this fundamental rule of procedural due process. E.g., Fed.R. Crim.P. 12.1(a) (notice of intent to offer a defense of alibi required); Fed.R.Crim.P. 12.2 (notice of intent to offer insanity defense or expert testimony of defendant’s mental condition).
As I see it, the reason that the government introduced the evidence at all was to permit the petit jury to infer that, since appellant possessed controlled substances three years previously, such prior possession was circumstantial evidence to establish possession of a controlled substance with intent to distribute in the instant case. This is directly contrary to the direction of Fed.R.Evid. 404(b). Since I do not believe that it was clear that the issues of mistake or accident would be in dispute, if the issues of mistake or accident were to be raised, it was for the defense to raise them by presenting evidence at the trial. The government could then have offered the prior act evidence in rebuttal. Cf. United States v. Simon, 842 F.2d at 555. *143But, it was error to admit them in the government’s ease in chief.
For these reasons, I respectfully dissent.
. Fed.R.Evid. 404(b) provides:
(b) Other crimes, wrongs, or acts. Evidence of other crimes, wrongs, or acts is not admissible to prove the character of a person in order to show action in conformity therewith. It may, however, be admissible for other purposes, such as proof of motive, opportunity, intent, preparation, plan, knowledge, identity, or absence of mistake or accident.