Thomas Matthew Crooks took his father’s AR-15, climbed a building near former President Donald Trump’s July 13 rally and got several shots off in Trump’s direction before being killed by the U.S. Secret Service. The gun was purchased legally in Pennsylvania by Crooks’ father. Early background reports indicate that the 20-year-old gunman was a loner, a registered Republican, but had also donated to at least one left leaning organization.