On December 12, at approximately 3:45 p.m.,  a school resource officer was driving in the 1000 block of Elmwood Avenue, when he observed a 13-year old male juvenile from Evanston who looked to be upset.  The juvenile told the officer that he was walking on the sidewalk when a male subject came up from behind him, brandished a handgun and demanded his JBL speaker that he had attached to the side of his book bag.  The victim described the suspect as wearing a black jacket with a red hooded sweatshirt, said Commander Joe Dugan of the Evanston Police Department.  

Detectives searching the area observed a male juvenile matching the description of the suspect walking in the 1400 block of Oak Avenue.  When the detectives pulled over to speak with the juvenile, he fled on foot.  Detectives began chasing the juvenile and observed him slip on some ice, fall to the ground and toss what appeared to be a black handgun under a parked vehicle.  The juvenile was taken into custody and upon recovery the handgun was determined to be a BB gun that resembles a real handgun, said the Commander.

The 15-year old juvenile suspect from Chicago was petitioned to juvenile court for felony aggravated robbery, said the Commander.