Police are investigating a shooting at a Yonkers apartment building.Officials say the incident occurred around 7:30 p.m. Sunday on Orchard Street. According to police, 15-year-old Koran Lockheart was shot in the chest in the hallway outside his apartment. Police say Lockheart was in an altercation earlier in the day and that the shooting may have been retaliation.Officials say Lockheart is in stable condition.Police have charged 23-year-old Matthew Payton, of Stanley Avenue, with the shooting.