F.B.I. Begins Inquiry in Deputy's Killing of 13-Year-Old Boy SAN FRANCISCO - The F.B.I. is investigating the fatal shooting of a 13-year-old boy by a sheriff's deputy in Northern California. A replica assault rifle that the teenager was carrying before being shot by sheriff's deputies in Santa Rosa, Calif., on Tuesday. Sheriff Steve Freitas of Sonoma County said in a statement Friday afternoon that he would cooperate fully with federal investigators and that he welcomed their participation. The shooting of the boy, Andy Lopez, in Santa Rosa on Tuesday has generated numerous protests and marches, with many residents questioning the deputy's decision to fire on the boy. Sheriff Freitas also expressed sympathy to the Lopez family and thanked the community for keeping protests peaceful. The police say the teenager was carrying a pellet gun that looked like an AK-47 assault rifle. A timeline released on Thursday by the Santa Rosa police shows that only 10 seconds passed from the moment that the sheriff's deputy and his partner called dispatch to report a suspicious person to the moment they called back to say shots had been fired. An F.B.I. spokesman, Paul Lee, said he did not know why his agency had decided to get involved or whether the local authorities had requested its help. More than 100 angry middle and high school students walked to City Hall on Friday, The Santa Rosa Press Democrat reported. Hundreds of people protested earlier in the week. City police and the Sonoma County district attorney's office are also investigating. The Santa Rosa Police Department said two sheriff's deputies in a squad car encountered the boy, who was wearing a hooded sweatshirt, around 3:15 p.m. on Tuesday. Witnesses say that at least one of the deputies took cover behind an open front door of the cruiser and that one yelled "drop the gun" twice. Ten seconds after their initial report to dispatch, one of the officers called in that "shots have been fired." Sixteen seconds later, the deputies were calling for medical help. The boy was pronounced dead at the scene. The Sonoma County coroner said he found seven "apparent entry wounds," two of them fatal. The deputies, who have not been identified, have been placed on paid administrative leave. Assistant Sheriff Lorenzo Duenas told The Press Democrat that the deputy who shot the teen is a 24-year veteran and that his partner, who did not fire his weapon, is a new hire.