HEMET (CBSLA.com) — Authorities have decided to not charge an 18-year-old driver who struck students outside Hemet High School in May.

Following initial reports that Daniel Carrillo may have been speeding, the California Highway Patrol has now determined the brakes of his pickup truck malfunctioned.

Carrillo, a junior at Hemet High, was going nearly 50 mph when he plowed into eight students and a 60-year-old woman just after school got out. He was reportedly driving a modified 1994 Ford Ranger as the vehicle ran a red light and jumped into a crosswalk on Stetson Avenue. Three of the students hit were seriously injured.

The driver told investigators that faulty brakes caused the collision.

The Riverside County District Attorney’s Office announced Monday that Carrillo will not face criminal charges. Instead, they have referred the matter back to CHP and Carrillo will likely be issued a traffic citation for the truck’s mechanical issues.

RELATED STORY: CHP Finds Speeding, Not Faulty Brakes, To Blame For Hemet High School Crash