Updated

Investigators say a 13-year-old boy was fatally wounded by a California sheriff's deputy before a second officer was able got out of a patrol vehicle and take cover.

Santa Rosa police Lt. Paul Henry disclosed the information to the Press Democrat of Santa Rosa (http://bit.ly/1clAGJC) in a story Tuesday. The details indicate just how quickly the incident unfolded.

Investigators say Sonoma County sheriff's Deputy Erick Gelhaus shot and killed Andy Lopez in Santa Rosa on Oct. 22 after he mistook a pellet gun Lopez was carrying for an assault rifle.

The second deputy, who has not been identified, did not fire.

Henry says that deputy told investigators that Gelhaus had already engaged Lopez and ended the threat by the time he exited and took cover.