Tamara A. Steckler, The Legal Aid Society, New York (John A. Newbery of counsel), for appellant.

Zachary W. Carter, Corporation Counsel, New York (Michael J. Pastor of counsel), for presentment agency.

Order of disposition, Family Court, Bronx County (Gayle P. Roberts, J.), entered on or about August 26, 2014, which adjudicated appellant a juvenile delinquent upon his admission that he committed the act of unlawful possession of a weapon by persons under 16, and placed him with the Administration for Children's Services for a period of 12 months, unanimously affirmed, without costs.

The court properly denied appellant's suppression motion. There is no basis for disturbing the court's credibility determinations. At the time that an officer saw what he recognized as the grip of a pistol protruding from appellant's waistband, the police had engaged in nothing but surveillance and had not interfered with appellant in any way (see People v Thornton, 238 AD2d 33, 36 [1st Dept 1998]). This observation provided reasonable suspicion that appellant was armed (see People v Prochilo, 41 NY2d 759, 762 [1977]), which justified police pursuit when appellant fled upon the officers' approach. In any event, appellant's pattern of suspicious behavior before the officer saw what appeared to be a pistol, which included, among other things, appellant's repeated fidgeting with his waistband and nervously looking over his shoulder as he walked away, provided a founded suspicion of criminality that would have justified a common-law inquiry (see e.g. People v Rodriguez, 207 AD2d 669 [1st Dept 1994], lv denied 84 NY2d 939 [1994]). Concur—Mazzarelli, J.P., Acosta, Saxe and Richter, JJ.