CONYERS, Ga., May 21 (UPI) -- Authorities have charged a 15-year-old with one count of aggravated assault in connection with a shooting that wounded six students at a suburban Atlanta high school. Rockdale District Attorney Richard Read says he anticipates filing as many as 30 counts of aggravated assault against the suspect in Juvenile Court as soon as today and will seek to have the charges transferred to Superior Court next week. Rockdale County Sheriff Jeff Wigington says police seized a .22- caliber rifle and a handgun from the youth, who put the handgun in his mouth before surrendering to an administrator at Heritage High School in Conyers, about 25 miles east of Atlanta, minutes after the shooting. Friends of the accused teenager, who has not been publicly identified by authorities, say he was distraught about the end of a two-year relationship with a girlfriend. Student Nathaniel Deeter says his classmate told him minutes before the shooting that he was ``real mad'' about the break-up. The former girlfriend was not among those wounded in Thursday's shooting. Another student, Jeff Dunn, says the 15-year-old was fascinated with guns and that his stepfather had a collection of guns that ``weren't really locked up.'' The suspect's family had moved to Conyers from Kernersville, N.C., three years ago, the Winston-Salem Journal reports today. The newspaper says the boy's stepfather was a terminal manager for Allied Systems in Kernersville before being transferred to Georgia in 1996. Four of the shooting victims remained hospitalized. All are in stable condition. The most seriously injured is 15-year-old Stephanie Laster, who underwent surgery for a bullet wound to her buttocks and intestines. She is expected to be released from an Atlanta hospital early next week. Heritage High School, which has an enrollment of about 1,400, remains closed today. Next week's classes will be the last of the school year. The high school, which has video surveillance cameras in the hallways and an armed sheriff's deputy, was named one of the top schools in the Atlanta area by U.S. News & World Report and about 80 percent of its graduates go on to college.  