Article continues below advertisementFederal prosecutors have released several chilling videos of Cole Tomas Allen, the 31-year-old California man accused of attempting to assassinate President Donald Trump during the White House Correspondents' Association dinner.Surveillance video from April 24 shows Allen casing a hallway and visiting the gym at the Washington Hilton the day before the attack.Security camera footage from the night of the gala on April 25 captures Allen storming through a security checkpoint with a 12-gauge pump-action shotgun in his hands.