A California deputy won't face criminal charges for shooting and killing a young teenager holding a pellet he mistook for an assault rifle.

Sonoma County District Attorney Jill Ravitch spoke at a news conference and said that Deputy Erick Gelhaus acted in self-defense when he shot 13-year-old Andy Lopez multiple times, The Associated Press reports.

"While in the lawful performance of his duty, Deputy Gelhaus was faced with a highly unpredictable and rapidly evolving situation," she said. "He believed honestly and reasonably that he was face with a do-or-die dilemma."

Lopez's parents were devastated by the news saying that it felt like their son "had been killed again" and they couldn't accept the prosecutors' decision.

The fatal shooting happened back on Oct. 22, 2013 while the young teen was walking around his neighborhood with the pellet gun, according to CBS SF.

Santa rosa Police Lt. Paul Henry said that Gelhaus claimed that Lopez turned in the direction of the deputy, who then thought "he was going to be shot" so fired several times. Lopez was hit by seven of the eight rounds.

While there will be no criminal charges forthcoming, Gelhaus will likely face a wrongful death lawsuit the teen's family filed, but had put on hold during the investigation into the shooting.