
46 N.Y.2d 767 (1978)
The People of the State of New York, Respondent,
v.
Jacob Luciano, Appellant.
Court of Appeals of the State of New York.
Argued October 20, 1978.
Decided December 7, 1978.
Philip I. Beane for appellant.
Mario Merola, District Attorney (Edward G. Spell, Alan D. Marrus and Barbara Gonzo of counsel), for respondent.
Chief Judge BREITEL and Judges JASEN, GABRIELLI, JONES, WACHTLER, FUCHSBERG and COOKE concur.
*768MEMORANDUM.
The order of the Appellate Division should be affirmed.
On the present record, the trial court properly refused to charge the jury that it could consider lack of motive in *769 determining defendant's guilt. Although in some circumstances absence of motive evidence may tend to establish that defendant did not commit the act charged or that he lacked the requisite intent (see, e.g., People v Sangamino, 258 N.Y. 85, 87-88; People v Guadagnino, 233 N.Y. 344, 348-349), here the commission of an intentional act was not in issue due to defendant's own testimony and self-defense plea (see People v Johnson, 139 N.Y. 358, 362).
Nor did the court err by refusing to entertain defendant's constitutional challenge to his prior convictions at the persistent felony offender hearing. While we agree that CPL 400.20 authorizes such a challenge, defendant did not allege that the prior convictions were "unconstitutionally obtained" within the meaning of that section. Rather, he claimed that his rights under People v Montgomery (24 N.Y.2d 130) were violated during the earlier proceedings. Even if this were so, the prior convictions would not be rendered invalid for the purposes of determining persistent felony offender status. At most, a Montgomery violation, if proven, would entitle defendant to an extension of time for taking an appeal (People v Corso, 40 N.Y.2d 578, 580-581).
We have examined defendant's remaining contentions and find them to be without merit.
Order affirmed in a memorandum.
