MARTINEZ — County prosecutors have filed seven felony counts against an 18-year-old student allegedly found with loaded guns at a Concord high school, according to court records.

The charges carry special allegations that Pittsburg resident Alejandro Cortes committed “street terrorism” as a member of a Northern California gang. He faces multiple charges of gun possession on school grounds, possessing ammunition, and possessing a large-capacity magazine.

The charging documents say Cortes has a prior robbery conviction. He was arrested at Olympic High school Feb. 28 after Concord officers responded to a report of a student at the school who might be armed.