The girl, who is a freshman, had just gotten off a PACE and was walking northbound on Central Avenue from 79th Street on her way to St. Laurence High School at about 7:40 a.m. when police said she was approached by the suspect from behind.
The suspect threatened the victim with a gun, forced her into an alley behind a garage and sexually assaulted her. She was taken to a local hospital for treatment and is now recovering at home.
The suspect fled east on 79th Street toward Central Avenue, where his image was captured on a private home's surveillance camera.
The Burbank Police Department hasn't released the suspect's name or age, since charges haven't yet been filed.
Police said video surveillance played a part in the investigation.
The suspect has been described as black, 17-20 years old, between 5'9"-5'11" and about 150-170 pounds. He was wearing a reddish-orange pull-over sweatshirt, black pants and carrying a black backpack.