It’s not clear if a bullet or shrapnel hit former President Donald Trump’s ear, FBI Director Christopher Wray told the House Judiciary Committee.

"With respect to former President Trump, there's some question about whether or not it's a bullet or shrapnel that hit his ear," Wray said in response to a question from Chairman Jim Jordan asking whether the FBI has accounted for all bullets fired by the shooter. "It's conceivable, although as I sit here right now, I don't know whether that bullet, in addition to causing the grazing, could have also landed somewhere else. But I believe we've accounted for all the shots in the cartridges."

FBI agents determined Crooks' father purchased the firearm used in the shooting in 2013 and sold it to his son in October 2023, Wray said.

-ABC News’ Luke Barr and Alex Mallin

The shooter, Thomas Matthew Crooks, accessed the roof of the AGR building using mechanical equipment on the ground and piping on the side of the building, FBI Director Christopher Wray told the House Judiciary Committee.

Crooks visited a gun range a day before the shooting, Wray said.

Authorities have interviewed Crooks’ parents, who Wray describe as "cooperative."

"It's the FBI position right now that he still acted independently," he said.

Wray said he was about to have dinner with family when he heard about the shooting. He said he was "horrified and angry."

-ABC News’ Luke Barr

It appears the shooter, 20-year-old Thomas Matthew Crooks, was a "loner" and didn't have a lot of contacts in his phone, FBI Director Christopher Wray told the House Judiciary Committee.

"A lot of people describe him as a loner. That does kind of fit with what we're seeing in his devices, you know, his list of contacts, for example, is very short, compared to what you would normally see from most people. Doesn't appear to be a whole lot of interaction between him, you know, face-to-face or digital, with a lot of people," Wray said.

The FBI has conducted over 400 interviews, with "many more to conduct," he said.

-ABC News’ Luke Barr

The weapon used by the gunman had a "collapsible stock," meaning Thomas Matthew Crooks could easily conceal the gun at the rally, FBI Director Christopher Wray told the House Judiciary Committee.

"The weapon had a collapsible stock, which could explain why it might have been less easy for people to observe," he said.

Wray said that the shooter was not on the FBI's radar and there were no FBI assets at the rally.

Wray said there were 14 guns in the home where Crooks lived.

-ABC News’ Luke Barr

Secret Service Director Kim Cheatle told the House Oversight Committee on Monday that the assassination attempt was "the most significant operational failure at the Secret Service in decades."

"There are multiple ongoing investigations into this incident, hundreds of people to interview, and thousands of documents to review. I do not want to inadvertently provide you today with inaccurate information," she said. "I may not be able to speak specifically to certain items that have circulated over the past nine days."

Cheatle said 36 people are currently under Secret Service protection, including Israeli Prime Minister Benjamin Netanyahu, who arrives in the U.S. on Monday.

"Immediately following the assassination attempt, I directed the activation of my Crisis Center and assembled my executive team to begin surging more protective resources to the former president and to ensure the wellness of our people post-incident, all while securing an active crime scene," she said.

Cheatle said she is not blaming state and local partners and said planning for the event began 10 days before the rally.

"The level of security provided for the former president increased well before the campaign and has been steadily increasing as threats evolve," she said. "The security plan included a full assessment of the Butler Farm show grounds to identify security vulnerabilities and craft a security plan for our protectee, attendees and the public."

-ABC News’ Luke Barr