Judgment unanimously affirmed. Memorandum: It was not an abuse of discretion for the suppression court to preclude cross-examination of a police witness concerning acts committed by the "hit squad", to which the witness occasionally was assigned (see, People v Chatman, 186 A.D.2d 1004). The extent of the cross-examination of a witness concerning collateral issues designed only to impeach that witness' credibility is within the sound discretion of the court (see, People v Sorge, 301 N.Y. 198, 201-202). In our view, the court did not abuse its discretion by refusing to allow cross-examination of a police witness on matters immaterial to the issues to be resolved at the suppression hearing.