Would-be Donald Trump assassin Thomas Matthew Crooks purportedly wrote a chilling online message that hinted at his sinister plans for the day he shot up the former president’s Butler, Pa. rally over the weekend. “July 13 will be my premiere, watch as it unfolds,” the 20-year-old gunman allegedly wrote on Steam, a popular online platform where gamers communicate, Fox News reported. Investigators are currently working to determine whether the posting is legitimate. The foreshadowing was revealed to US senators during a briefing by top law enforcement officials Wednesday.