Matthew Livelsberger left behind a trove of information investigators are still sorting through. He said the attack was a 'wake-up call.'

Las Vegas police and FBI officials shared more information about the man in the Tesla Cybertruck that exploded outside a Trump hotel in Las Vegas on New Year's Day. Authorities say he was a decorated Army veteran likely suffering from post-traumatic stress disorder and that they found documents on his phone criticizing the U.