Anjohnito Willett Jr. awaited arraignment late Wednesday on four counts each of attempted homicide, aggravated assault and reckless endangerment. He's also charged with illegally possessing a gun as a juvenile.
Police Lt. Kevin Kraus says Willett wounded three students and shot at a fourth as they were headed to a car to drive home from classes at Brashear High School on Wednesday afternoon.
Kraus says school police investigated the Oct. 18 robbery but couldn't file charges because Willett wouldn't identify his attackers, telling police he wished to settle matters himself.
Willett was in custody and it wasn't clear whether he has an attorney.