The gunman in July’s assassination attempt on former President Donald Trump gained access to the roof he fired from by getting atop an air-conditioning unit, a source briefed on the investigation into the shooting said.
Trump was shot in the ear on July 13 during a rally in Butler, Penn., one rallygoer was killed and two others were wounded before a Secret Service counter-sniper shot and killed the 20-year-old gunman.
The source said video recorded from a nearby ice cream shop shows the shooter using an air-conditioning unit to climb onto the rooftop of a building to get into position about 450 feet from where Trump was starting his speech.
NBC News has not reviewed the video, and it is not clear if it will be made public.
Investigators have been working to determine how the gunman was able to get on top of the roof without being detected. They discovered that Thomas Crooks of nearby Bethel, Penn., purchased a ladder ahead of the incident, but ruled out that one was used to gain access to the roof.
Multiple witnesses say they saw Crooks on the roof moments before the shots rang out, and a local police officer climbed up, saw him with a gun and radioed a warning. But that warning never made it to the Secret Service agents protecting Trump, the agency’s director testified, and around 40 seconds later the shots were fired.
Investigators have said they believe Crooks used a gun with a collapsable barrel that allowed him to move through the crowd with the weapon undetected.
The building was outside a security perimeter established by the Secret Service, but it provided a clear shot at the former president. It houses a plastics and glass company.
Earlier this summer, Kimberly Cheatle stepped down as director of the U.S. Secret Service after widespread calls from lawmakers for her to resign after the shooting.
Multiple Secret Service officials have been put on leave for their actions leading up to and responding to the assassination attempt, including the Secret Service’s special agent in charge of the Pittsburgh field office, whose office was responsible for coordinating the security plan with local law enforcement leading up to the rally.
Last week in Asheboro, N.C., Trump held his first outdoor rally since the assassination attempt, speaking from behind bulletproof glass.
This article was originally published on NBCNews.com
