Ordered that the judgment is reversed, on the law, and a new trial is ordered.
After a jury trial, the defendant and his codefendant, Everad Salomon, were convicted of first and second degree robbery in connection with a gunpoint robbery on a Queens street. Viewing the evidence in the light most favorable to the prosecution ( see, People v. Contes, 60 N.Y.2d 620), we find that it was legally sufficient to establish the defendant's guilt beyond a reasonable doubt. Moreover, upon the exercise of our factual review power, we are satisfied that the verdict of guilt was not against the weight of the evidence ( see, CPL 470.15).
The defendant's conviction must be reversed, however, because he was substantially prejudiced by the People's failure to provide certain Rosario material related to a critical aspect of the complainant's testimony until after she had been cross-examined. As a result of the People's delay in providing the material — a record book maintained by the complainant which was in the People's control — damaging testimony was unwittingly elicited during her cross-examination. The court refused to strike the testimony, but instead gave the jury an adverse inference charge regarding a different document which the People had failed to produce.
Rosario material must be provided at a time when it meaningfully can be used to prepare cross-examination. "The fairness concept embodied in the Rosario rule cannot be said to have been satisfied when pretrial statements revealing a potential trap for the cross-examiner are furnished to defense counsel only after the trap has sprung" ( People v. Perez, 65 N.Y.2d 154, 159). Here, the prosecutor deliberately withheld information which was likely to be elicited on cross-examination and would be damaging to the defense. Consequently, reversal is required ( see, People v. Perez, supra).
In light of our determination, we need not address the defendant's remaining contentions.
O'Brien, J.P., Joy, Altman and Luciano, JJ., concur.