The gunman involved in Saturday’s synagogue shooting at Poway, California that left one dead and three injured has been identified as 19 year old John Earnest.<br /><br />San Diego County Sheriff Bill Gore said investigators were examining a "manifesto" the gunman apparently left behind on social media along with other "digital evidence."<br /><br />Gore also said police and FBI were investigating Earnest's "possible Involvement" in an unsolved arson fire at a nearby mosque about a month ago.