The gunman who tried to assassinate Donald Trump fired from a rooftop that the U.S. Secret Service had declared to be outside its security perimeter

The gunman who attempted to assassinate Donald Trump fired from a rooftop that the U.S. Secret Service had deemed outside its security perimeter—a significant oversight, according to two former officials of the agency.

Two local Pennsylvania police officers, responding to a dispatch call about a suspicious person in the area, encountered the gunman, 20-year-old Thomas Crooks. One officer, hoisted up by his partner to check the roof, confronted Crooks, Butler County Sheriff Michael Slupe said in an interview.

Kenneth Valentine, a former Secret Service special agent in charge, highlighted this security lapse: "He shouldn't have been able to get up on the roof." Valentine added that the agency should have had personnel monitoring the rooftops as a second line of defense to stop any threats.

The Secret Service, responsible for Trump's safety as a former president and current Republican presidential candidate, did not respond to multiple requests for comment. After the shooting, the agency stated that the building, approximately 150 yards (140 meters) from the stage where Trump was speaking, was outside the secured area for the outdoor event. Local and state police also said it was not their responsibility.

This oversight allowed Crooks to access the roof without hindrance and fire at Trump, grazing his ear, killing a rallygoer, and wounding two other attendees. "The Secret Service said the building was outside the perimeter. That’s not true. That should have been within the perimeter," said a former Secret Service agent. "This is a massive failure."

Both former Secret Service officials asserted that the agency should have identified the building as a security risk and ensured it was inaccessible.

President Joe Biden has ordered an independent review to determine how the gunman came so close to killing Trump despite the heavy security at the event in Butler, Pennsylvania. The agency is also facing investigations from Congress.

Sheriff Slupe told Reuters that Butler County sheriff's deputies were not responsible for security inside or outside the perimeter. The Pennsylvania State Police, who also staffed the event, stated they were not responsible for securing the building owned by packaging equipment company AGR International.