Appeal by the People from an order of the County Court, Suffolk County, dated February 5, 1980, which, without a hearing, granted defendant’s motion to dismiss the indictment on the ground that he had been denied a speedy trial. Order reversed, on the law and the facts, and matter remitted to the County Court for a hearing and new determination on defendant’s motion to dismiss, with special attention to be given to the periods of delay from August 9, 1979 to October 9, 1979 and December 10, 1979 to January 7, 1980. As respects the period from August 9, 1979 to October 9, 1979, the People assert, but do not substantiate, that they made diligent efforts to locate the defendant during this time period. Mere assertion that the People have made a good faith effort to locate a defendant is insufficient to overcome the right to speedy trial relief; it is incumbent upon the prosecution to establish periods of exclusion pursuant to CPL 30.30 (subd 4) which justify delay (People v Williams, 67 AD2d 1094; People v Scott, 54 AD2d 939). In addition, the record is incomplete with respect to the reason for the delay from December 10, 1979 to January 7, 1980. Where questions of fact are presented, a hearing must be held by the court prior to making a determination of the motion (People v Gruden, 42 NY2d 214; People v Williams, supra; People v Scott, supra). Since the burden is on the People to establish periods of exclusion under CPL 30.30 (subd 4), the case is remanded for further proceedings. On remand, the court will conduct a hearing and make appropriate findings in accordance with CPL 30.30 (subd 4) (see People v Williams, supra; People v Del Valle, 63 AD2d 830; People v Cook, 63 AD2d 842). We also note that the trial court improperly charged the People with the period of delay from October 9, 1979 to November 5, 1979 (see CPL 30.30, subd 4, pars [b], [c], [e]). Hopkins, J. P., Mangano, O’Connor and Weinstein, JJ., concur.