How does a gunman, in plain view of some spectators, manage to open fire on a former president at a campaign rally protected by federal and local law enforcement?
That is the frightening and unanswered question facing the country — and security officials — after Donald Trump said he suffered a graze wound on his right ear while he was speaking in a field in Butler, Pennsylvania, and left the stage with a bloodied head.
Secret Service personnel shot and killed the gunman, identified as Thomas Matthew Crooks of Bethel Park, Pennsylvania, immediately after he opened fire, the FBI said. A spectator was killed and two additional spectators were injured, but it was not immediately clear who shot them.
The assassination attempt, in which Crooks fired multiple shots at the stage from a roof outside the venue’s security perimeter, appeared to be the result of a grave lapse, perhaps the biggest since President Ronald Reagan was shot and wounded outside a Washington hotel in 1981.
Security experts said it was difficult, and perhaps impossible, to eliminate every threat, particularly with long-range weapons and outdoor events.
But some said routine precautions should have prevented the shooter from getting onto the nearby roof.

Steve Nottingham, a former SWAT commander in Long Beach, California, called Saturday’s shooting “a fundamental security failure.”He has worked security details for visiting world leaders, including presidents, and now trains officers on how to respond to critical incidents. He pointed at likely breakdowns in the pre-event scouting and real-time monitoring of places a gunman could shoot from.
“They were behind the curve, because they should have had those places covered ahead of time,” Nottingham said.
Jim Cavanaugh, a retired special agent in charge with the Bureau of Alcohol, Tobacco, Firearms and Explosives who has been on Secret Service details, said he was surprised that the shooter was able to occupy an elevated position within rifle range of the rally site.
“Whenever I’ve been with them, every single high ground is taken by them or the local SWAT police,” Cavanaugh said. “There’s nobody allowed walking on rooftops. They command the high ground.”
He said a high-powered rifle like an AR-15 can hit targets 200 yards away. Trump was about 148 yards from the rooftop where the shooter was found dead, NBC News found, based on an analysis of Google Earth images.
Cavanaugh added: “Having been on Secret Service details, it’s amazing to me that somebody was on an elevated position that they didn’t know about.”Pennsylvania State Police Lt. Col. George Bivens defended the Secret Service at a news conference after the shooting.
“It is incredibly difficult to have a venue open to the public and to secure that against any possible threat against a very determined attacker,” Bivens said. “That’s a huge lift.”
“The investigation will really give us an opportunity to take a look at where any failures occurred and what can be done better in the future,” he added.
The Secret Service did not immediately respond to a request for comment.
The FBI is leading the investigation, including its crisis response team members and evidence response technicians, it said in a statement Saturday evening.

Last month, as the presidential campaign heated up, the Secret Service said it was increasing the size of the detail assigned to Trump. The protection was bulked up “to ensure the highest level of security for not only the event sites but the travel in between events,” Secret Service spokesman Anthony Guglielmi said at the time.Perhaps the first sign that something was going wrong as Trump spoke Saturday came when spectators said they noticed a man with a rifle bear-crawling on a nearby roof. One recalled trying to get the attention of law enforcement.
“The police are down there running around on the ground. We’re like, ‘Hey man, there’s a guy on the roof with a rifle,’” the witness told BBC News. “And the police were like, ‘Huh, what?’ Like they didn’t know what was going on. We’re like, ‘Right here on the roof. We can see him from right here. We see him. He’s crawling.’”





