 An AR-15 type semi-automatic rifle was found next to Mr. Crook's body. Investigators said on Sunday that while the weapon had been purchased by the gunman's father, they did not know how the gunman took possession or whether he had used it without his father's knowledge. Well, come on. Hey, Dad, I'm going to take the AR-15. What do you need it for? Oh, I'm going to a Trump rally. Come on.