 We're learning more about the gunman who tried to kill former President Trump in Pennsylvania last weekend. CBS's Meg Oliver. 20-year-old shooter Thomas Matthew Crooks. He visited the site of the attack at least once before the rally. Investigators have yet to discover a motive. Senators at the Republican Convention chased Secret Service Director Kimberly Cheadle, demanding answers about security failures at the rally. What a long, strange trip it's been for this year's Kennedy Center honorees.