Defendant has been convicted of criminally selling a controlled substance (heroin), to an undercover agent of the Erie County Sheriff’s Department. A new trial is required because the prosecutor improperly cross-examined defendant during the trial about his prior drug conviction and other drug-related incidents.
Prior to trial defendant moved for a Sandoval hearing (People v Sandoval, 34 NY2d 371). At the conclusion of that hearing the court ruled that if defendant testified, the District Attorney might question him about the underlying facts of (1) a 1971 charge of criminal possession of a hypodermic instrument which had been dismissed by City Court at the request of the District Attorney "without prejudice”, (2) a 1971 charge of possession of a weapon and (3) a 1971 charge for attempted possession of dangerous drugs, fourth degree which resulted in conviction and a sentence of probation for five years with defendant receiving treatment. The hypodermic arrest and the attempted possession conviction apparently arose out of the same incident. It is this ruling and the cross-examination permitted by the court on these matters which defendant assigns as error.
When a defendant’s prior bad acts are introduced into *266evidence, two possible inferences arise, one permissible and one impermissible. The permissible inference is that one who has sinned in the past may have less respect for the truth than someone who has not. The impermissible inference is that one who has sinned before has sinned again and is guilty of the crime charged. Thus, the rule is stated that a defendant who chooses to testify may be cross-examined as to any immoral, vicious or criminal act which has a bearing upon his credibility as a witness, but he may not be questioned about such acts if the intent of the questions is to show from defendant’s character or experience that he is predisposed to commit the crime for which he is on trial (People v Schwartzman, 24 NY2d 241, cert den 396 US 846; People v McKinney, 24 NY2d 180, 184; People v Reingold, 44 AD2d 191). If the "prejudicial effect of the impeachment testimony far outweighs the probative worth of the evidence on the issue of credibility,” then the evidence should not be admitted (People v Sandoval, supra, p 376). Quite naturally, as the nature of the prior bad act and the crime charged become more similar, the inclination to consider the prior act as evidence of guilt becomes more irresistible.
In Sandoval (supra, p 378) the Court of Appeals attempted to set "some boundaries to the scope of cross-examination permitted in the past” and made two observations pertinent to the issue on this appeal. It stated that (pp 377-378): "crimes or conduct occasioned by addiction or uncontrollable habit, as with alcohol or drugs * * * may have a lesser probative value as to lack of in-court veracity” and "in the prosecution of drug charges, interrogation as to prior narcotics convictions * * * may present a special risk of impermissible prejudice because of the widely accepted belief that persons previously convicted of narcotics offenses are likely to be habitual offenders (United States v. Puco, 453 F. 2d, at p. 542, n. 9).” (See, also, People v Yost, 50 AD2d 577; cf People v Duffy, 36 NY2d 258 [in which questions about drug activities were permitted during a trial on non-drug related charges]). The danger pointed out by the court in the Sandoval decision is evident in this case.
Defendant was charged with a crime occurring during a one-on-one street sale. True enough, the encounter was observed by two back-up Deputy Sheriffs from a distance, but full evidence of the sale could be supplied only by defendant and the Sheriff’s undercover agent, a witness who also possessed a criminal record including drug offenses. There was, *267therefore, a compelling need for the jury to hear defendant’s testimony. The court’s ruling, however, created a serious risk of prejudice to him if he took the witness stand by permitting cross-examination of his prior drug activities, not only because of the similarity of the offenses, but because of the widespread acceptance of the notion that the drug users are habitual offenders and necessarily violate the law to supply their habits.1
Notwithstanding the court’s ruling in the Sandoval hearing, defendant chose to testify and admitted on direct examination that he had been arrested for the weapon and drug possession charges in 1971 and that he had pleaded guilty to "intent to buy” drugs (attempted possession) and had been sentenced to five years’ probation.2 On cross-examination the prosecutor’s questions about these incidents and his drug habits cover some 20 pages of the record and on recross-examination the prosecutor reopened the subject and again questioned at length. The prosecutor’s questioning went far beyond the pale of proper impeachment and all but invited the jury to adopt the impermissible inference of guilt from this testimony by discussing in detail not only the long history of defendant’s drug addiction, the cost of defendant’s habit and the fact that at times the cost exceeded his earnings, but also by interrogating defendant about crimes similar in nature to the crime defendant was charged with (cf People v Duffy, 36 NY2d 258, supra). The obvious purpose of this and the reference to 17 hypodermic needles allegedly found at the scene of the crime for which defendant pleaded guilty (instruments of which defendant denied knowledge and which he was not charged with possessing) was not to reflect on defendant’s credibility, but to suggest that crime, particularly trafficking in drugs, was a necessary practice of defendant to support his admitted habit.
*268While the examination on the weapons charge was proper under accepted rules and evidence of prior drug activities may in some cases be harmless error, the questioning on the drug related incidents in this case could only have had a disproportionate impact upon the minds of the jurors. A new trial is required at which evidence of defendant’s prior drug activity should be excluded (see People v Yost, 50 AD2d 577, supra; People v Santiago, 47 AD2d 476; cf United States v Harding, 525 F2d 84).
The judgment should be reversed and a new trial granted.
. That obvious prejudice did not prevent our affirmance of the sales conviction in People v Law (48 AD2d 228). That case is distinguishable, however, because the District Attorney’s questions were precipitated by the defendant’s statements on direct examination that he had never possessed or sold heroin at any time, in effect opening the door to the prosecutor’s questions that he had assaulted an officer on a previous occasion when he was arrested for drug sales.
. The dissent suggests that the defendant actually fared quite well inasmuch as the court permitted questioning on only three subjects and denied questions on nine. But the issue is whether the evidence permitted had a disproportionate prejudicial impact which outweighed its probative worth—not that defendant batted .750 at the hearing.