Federal officials have identified 20-year-old Thomas Matthew Crooks as the man who fired shots at former president Donald Trump Saturday during a political rally in Butler, Pennsylvania. Crooks, a registered Republican who reportedly donated $15 to a Democrat-focused voter turnout organization, was killed by Secret Service agents after firing shots that grazed Trump's ear, killed one rally attendee, and injured two others, officials say. An investigation into the motives behind the assassination attempt is ongoing.

Trump was just a few minutes into his speech at the rally when, per his Saturday post to social media, “I heard a whizzing sound, shots, and immediately felt the bullet ripping through the skin." The GOP front-runner is recovering well, a spokesperson says. At a Saturday night news conference, FBI special agent in charge Kevin Rojek said that they believed Crooks had fired his weapon, reportedly a semi-automatic AR-15 rifle, from an “elevated position” about 164 yards from the Butler Farm Show grounds where the rally was held. According to Pennsylvania State Police Lt. Col. George Bivens, the rooftop was “outside the perimeter” of the event.

“It is surprising," Rojek said of the shooter's access to the venue. “To get all the details of that will come out later in the investigation.”

Secret Service spokesperson Anthony Guglielmi says that Crooks was immediately “neutralized," but that his shots fatally struck one spectator, who was identified Sunday as Corey Comperatore, a former fire chief from the area, the Associated Press reports. Two other spectators were injured, with their conditions still unknown. Crooks was not carrying identification at the time of the attack, and was identified using “ biometric confirmations,” Bivens said.

Preliminary reports say that Crooks was a resident of Bethel Park, Pennsylvania, a Pittsburgh suburb about 43 miles from the site of the assassination attempt. Born on Sept. 20, 2003, Crooks graduated from Bethel Park High School in 2022. He had registered to vote as a Republican the previous year.

Also in 2021, Crooks reportedly donated $15 via Democratic fundraising platform ActBlue, to the Progressive Turnout Project, a donor-supported organization intended to encourage Democrats to vote. As of publication time, social media accounts or posts created by Crooks had not been identified. (Vanity Fair has reached out to Meta to understand if Crooks had accounts that had been removed, but did not receive a response as of publication time.)

According to some witnesses who observed Crooks's body following the shooting, he was wearing a shirt that advertised DemolitionRanch, a YouTube channel devoted to the capabilities of explosives and firearms. Via social media, channel host Matt Carriker posted a photo purportedly of Crooks's dead body, with the caption "What the hell."

Crooks was a "loner" who was “bullied so much in high school," high school classmate Jason Kohler told NBC News. Crooks would attend class in “hunting outfits and was made fun of for the way he dressed,” Kohler said.

According to the BBC, Crooks worked in the kitchen of a local nursing home. He did not have a criminal record in Pennsylvania, nor had he been sued there, USA Today reports. He did not serve in the U.S. military, Pentagon press secretary Maj. Gen. Pat Ryder said via a statement. “We’ve confirmed with each of the military service branches that there is no military service affiliation for the suspect with that name or date of birth in any branch, active or reserve component in their respective databases,” he said.

Crooks’ father, Matthew Crooks, has declined comment to the media, telling CNN Saturday night that he needed to “wait until I talk to law enforcement” before speaking with the press. Mary Crooks, the suspect's mother, has also declined to speak. According to multiple media outlets, law enforcement officials (who spoke anonymously) believe that Matthew Crooks bought the gun suspected to have been used by his son in the assassination attempt “at least six months ago.” It's unclear how his son obtained the weapon.

Anonymous law enforcement officials have also said that bomb-making materials had been found inside Crooks's car, and at his home. Vanity Fair has not been able to independently verify that, or the gun purchase details, as of publication; however, it's been confirmed that as of Sunday morning, all roads leading to and from the home Crooks shared with his family have been closed off as part of the investigation.

Speaking with the New York Times, an unnamed senior law enforcement official said that thus far, it appears that Crooks had been acting alone. However, they cautioned that the investigation was still in its earliest stages, and that his electronic devices had yet to be examined for connections to others.

When contacted by Vanity Fair for comment, the FBI declined to provide additional details, but did urge people with knowledge of the case to contact the agency immediately. “This remains an active and ongoing investigation,” they said via statement. “Anyone with information that may assist with the investigation is encouraged to submit photos or videos online at FBI.gov/butler or call 1-800-CALL-FBI.”