LOWELL -- A 17-year-old Ayer teen accused of assaulting and robbing 15-year-old Corey Buxton, who pursued his assailants and was hit and killed by a car, has had a hearing in which he was to plead guilty to the charges rescheduled.

Robert Malcolm is facing charges in Lowell Superior Court of assault with intent to rob, unarmed robbery, and assault and battery (two counts) in connection with the Jan. 4 incident.

Malcolm was scheduled to change his plea Tuesday, but the hearing was rescheduled to Nov. 22.

Prosecutor Sean Casey alleges that Malcolm and a juvenile, who isn't named, allegedly jumped out of the car and began assaulting the younger teens, stealing $20, allegedly with the intent to buy marijuana, then ran to the car and drove off.

Buxton stepped off the curb, trying to run after the assailants, and was hit by another car.

Malcolm allegedly saw Buxton "lying in the street and didn't stop" after he robbed him, Casey said. Rather, he fled, hopping into a car and driving off with others.