 Racing to put together a profile of Thomas Crooks. Sources confirming to ABC News Crooks bought dozens of rounds of ammunition from an online source and a local gun store in the days and weeks before the attack. And on the day of the rally, sources say Crooks, who had a membership at a local gun club, told his father he wanted to go to the shooting range. And that's when his father gave him the semi-automatic rifle, thinking nothing unusual about it.