Appeal by defendant from a judgment of the Supreme Court, Kings County, rendered October 13, 1971, convicting him of robbery in the second degree and grand larceny in the third degree, upon a jury verdict, and imposing sentence. Judgment reversed, on the law and as a matter of discretion in the interest of justice, and a new trial ordered. On the trial, defendant attempted to establish a defense of alibi. The trial court's charge to the jury on this point closely followed the alibi charge in People v. Johnson ( 37 A.D.2d 733) where it was held that to require the defendant to clearly establish the alibi by "`unsuspected believable testimony'" erroneously shifts the burden of proof and deprives him of a fair trial. While no exception was taken to this charge, defendant's guilt was not "overwhelmingly established" so as to permit us to regard the charge as harmless error ( People v. Anderson, 37 A.D.2d 728; cf. People v. Lorez, 28 A.D.2d 726, affd. 21 N.Y.2d 733). Additionally, we believe it was error to permit the prosecutor, on cross-examination, to inquire about sentences imposed upon prior convictions to which defendant had testified. Hopkins, Acting P.J., Latham, Gulotta, Christ and Brennan, JJ., concur.