The Secret Service is investigating how the man who shot Trump got as close as he did.
The gunman, who was killed by Secret Service personnel, fired multiple shots at the stage from an "elevated position outside of the rally venue," the agency said.
The roof was less than 150 meters (yards) from where Trump was speaking, a distance from which a decent marksman could reasonably hit a human-sized target.
The AR-15, like the shooter at the Trump rally had, is the semi-automatic civilian version of the military M16.
The Secret Service didn't have anybody at a late-night news conference where FBI and Pennsylvania State Police officials briefed reporters on the shooting investigation.
"We condemn this violence in the strongest possible terms and commend the Secret Service for their swift action today," Mayorkas said.
The FBI said it will lead the investigation into the shooting, working with the Secret Service and local and state law enforcement. »
