 Former GOP candidate Nikki Haley expected to be a keynote speaker at the RNC. We're learning more about the gunman, Thomas Crooks, who fired shots injuring Trump and killing a bystander Saturday. Investigators, though, say they still don't know why. ABC's Aaron Katursky is in Bethel Park, Pennsylvania. The FBI has conducted more than 100 interviews, many of them right here in the neighborhood where the shooter lived. They've gained access to his phone now. They even know how he was able to take possession of the rifle, but none of that has established a clear motive.