The U.S. Justice Department announced late Wednesday that it will not file criminal charges against a Sonoma County sheriff’s deputy who shot 13-year-old Andy Lopez, ending a federal civil rights investigation into the 2013 shooting.

“The decision to close the file without bringing charges was based upon the conclusion that there is insufficient evidence to prove that the deputy willfully used excessive force resulting in Andy’s death,” Justice Department spokesman Abraham Simmons said in a statement.

The decision comes one year after Sonoma County District Attorney Jill Ravitch concluded that Deputy Erick Gelhaus acted within the law when he shot Lopez as the teen walked down a southwest Santa Rosa sidewalk carrying an airsoft BB gun designed to look like an AK-47 rifle. An internal investigation by the Sonoma County Sheriff’s Office reached the same conclusion, the Press Democrat reports.