Troubling Signs Before Gunman Opened Fire at Trump Rally Unveiled

Signs of trouble emerged minutes before shots were fired at Donald Trump's rally in Pennsylvania. Police had received a report about a suspicious man pacing near the magnetometers and were sharing photos of the suspect. Witnesses pointed and shouted at an armed man on a nearby roof.

When a police officer climbed up to investigate, the gunman turned and pointed his rifle at him. However, the officer did not fire a shot. A sniper took down 20-year-old Thomas Matthew Crooks within seconds of him firing an AR-style rifle towards Trump, but it was too late.

Independent Investigation Ordered

President Joe Biden has called for an independent investigation into the attempted assassination. Homeland Security Secretary Alejandro Mayorkas expressed confidence in the Secret Service's leadership but acknowledged that the gunman should never have reached that position. "We are speaking of a failure," Mayorkas told CNN. "We are going to analyze through an independent review how that occurred, why it occurred, and make recommendations and findings to make sure it doesn't happen again."

At least a dozen police officers and sheriff's deputies were assisting the Secret Service and Pennsylvania State Police with rally security. Several rallygoers reported Crooks' suspicious behaviour near the magnetometers to local officers, according to a law enforcement official who spoke anonymously.

Officer's Encounter with Gunman

A Butler Township police officer encountered the gunman on the roof before the shooting. The officer was searching for the suspicious person when another officer hoisted him up so he could grab the edge of the roof, local officials said. The officer dropped back down to safety when the gunman pointed his rifle at him, according to Butler County Sheriff Michael Slupe.

Slupe, who was inside the rally venue during the shooting, said the officer could not have used his own gun under those circumstances. "I think all law enforcement on site did everything that they could, especially the local law enforcement," Slupe told The Associated Press on Monday. "I hope they're not made a scapegoat because they did their job to the best of their abilities."

Butler Township Manager Tom Knights said the officer lost his grip and was not retreating when he fell 8 feet to the ground. "He was literally dangling from the edge of a building and took the defensive position he needed to at that time. He couldn't hold himself up," Knights said.

FBI Investigation

The FBI is investigating the attack as a potential act of domestic terrorism but has not identified a clear ideological motive. The agency believes Crooks acted alone and had bomb-making materials in his car. The FBI has gained access to Crooks' cellphone and is analyzing all his electronic devices for clues about a possible motive.

The FBI has conducted nearly 100 interviews with law enforcement officials, rally attendees, and other witnesses. They have also received hundreds of digital media tips. Authorities believe Crooks' AR-style rifle was purchased by his father. Kevin Rojek, FBI special agent in charge in Pittsburgh, said investigators do not yet know if Crooks took the gun without his father's permission.

The roof where Crooks lay was less than 150 meters (164 yards) from where Trump was speaking, a distance from which a decent marksman could reasonably hit a human-sized target. This is a distance at which US Army recruits must hit a scaled human-sized silhouette to qualify with an M-16 rifle.

Two spectators were critically wounded in the shooting, and 50-year-old former fire chief Corey Comperatore was killed. The FBI has finished searching Crooks' home and car as part of their investigation.

The officer involved in encountering Crooks has 10 years of experience in law enforcement and severely injured an ankle in the fall, requiring him to wear a walking boot, Knights said.