The gunman who attempted to assassinate former President Donald Trump used a firearm with a “collapsible stock”, likely making it easier to conceal, FBI Director Christopher Wray has said.
Mr Wray is testifying on Tuesday before the House Judiciary Committee about the shooting at the Butler, Pennsylvania, campaign rally earlier this month.
A bullet grazed Trump’s right ear and the attack left one audience member dead and two others badly wounded.
Mr Wray also said the gunman researched the 1963 assassination of John F Kennedy in the days before the shooting.
In his opening remarks, Mr Wray called the attempted assassination of former President Trump “an attack on our democracy and our democratic process”.
“We will not and do not tolerate political violence of any time especially a despicable account of this magnitude,” he told lawmakers.
The FBI director said officials found eight cartridges on the roof where the gunman, identified as 20-year-old Thomas Matthew Crooks, was located.
Crooks was killed by a counter sniper during the incident.
The AR-style rifle used in the shooting had a collapsible stock, which can make a weapon shorter and easier to transport.
The first people to see the gunman with a rifle did so when he was already on the roof from where he fired, Mr Wray said.
He also confirmed that the gunman flew a drone over the rally about two hours before the shooting.
Additionally, the FBI found three “relatively crude” explosive devices – one in the gunman’s home and two others in his car.
These devices were capable of being detonated remotely and the gunman had a transmitter, Mr Wray said.
It did not appear as if Crooks would have been able to detonate them from the roof where he was perched at the time of the shooting, he added.
The FBI head said the agency still does not have a motive for the assassination attempt but the gunman appears to have become “very focused” on Trump from around 6 July.
On that day, the gunman searched for “how far was Oswald from Kennedy” and registered for the Trump rally, Mr Wray said.
Investigators also found the gunman had conducted searches for news articles about other public figures.
Mr Wray said there is no evidence that the gunman planned the attack with others.
The FBI is handling the criminal investigation into the attempted assassination and Mr Wray told the committee the agency will “leave no stone unturned”.
“The men and women of the FBI will continue to work tirelessly to get to the bottom of what happened,” he said.
Secret Service Director Kimberly Cheatle resigned from her position on Tuesday after testifying before a different congressional committee earlier this week.
