Twenty-year-old Thomas Matthew Crooks was identified by the FBI on Sunday as the shooter behind the attempted assassination of former President Donald Trump during a campaign rally in Butler, Pa., on Saturday evening that left one bystander dead and two others critically injured. Eyewitness Accounts What We Know So Far About the Gunman Politicians Condemn Shooting The Recent History of Political Violence in America Joe Biden’s Test Crooks was killed at the scene by a Secret Service sniper, and investigations continue into his motives, which remain unclear. [time-brightcove not-tgx=”true”] Here’s what we know so far. ‘No indication of any mental health issues’ The FBI says that Crooks was not known to the agency prior to the incident. In a call with reporters Sunday night, the FBI special agent in charge, Kevin Rojek, said there was “no indication of any mental health issues” regarding the shooter. Limited social media presence Rojek also said authorities “have not yet identified an ideology” associated with Crooks.