Thomas Matthew Crooks has been named as the gunman in the assassination attempt against Donald Trump on Saturday evening.
Mr Trump‘s ear was hit in the shooting, which killed one person and injured two others.
Shooting latest: Trump releases statement after assassination attempt
The US Secret Service said the gunman was “neutralised”.
Here is everything we know about Crooks at this point.
Who was the gunman?
The FBI named him as Thomas Matthew Crooks around seven hours after the shooting.
They had earlier said they were using biometrics to identify the gunman.
Law enforcement said Crooks was 20 years old and from Bethel Park in Pennsylvania.
Bethel Park is a predominantly white, relatively well-to-do city in the southern part of greater Pittsburgh. The site of the rally, Butler, is about an hour’s drive north of Pittsburgh.
A map showing the relative locations of Butler and Bethel Park
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Sky’s US partner network NBC News found that Pennsylvania voter records listed a Thomas Matthew Crooks, with the same address and birth date, as a registered Republican, though it was not clear when the record was from.
Not much else is known about Crooks’ life or upbringing at this point.
But he is believed to have won a National Maths and Science Initiative Star Award worth $500 (£393) on graduating from Bethel Park High School in 2022, according to local news site the Tribune Review.
He also appeared to wear merchandise promoting one of YouTube’s most popular channels devoted to firearms during the attack, NBC News reported.
He was wearing a grey T-shirt with an American flag on the sleeve and block lettering that was partially obscured in photos from the scene.
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Hear what secret service said to Trump
The appearance and lettering on the shirt matches the appearance of a shirt that is for sale on the website for firearm YouTube channel Demolition Ranch.
Read more:
‘Pop pop pop’ – Witnesses describe moment of shooting
In pictures: Gunman fires multiple shots at Trump rally
After online speculation grew about the gunman, NBC News reported that Demolition Ranch and its founder posted to social media, sharing photos of the shooting’s aftermath and writing: “What the hell.”
Demolition Ranch has over 11 million subscribers on YouTube, where the channel frequently posts videos about various types of firearms.
What happened during Saturday’s rally?
Crooks was allegedly on the roof of a building around 150m from where Donald Trump was speaking. He was situated outside the area secured by the Secret Service ahead of the rally.
He was immediately “neutralised” by the Secret Service after the shooting.
Witnesses said it wasn’t clear where the shots were coming from, with Pennsylvania police officer Lt Col George Bivens saying afterwards that “the shots were scattered somewhat and so they weren’t just into one particular location.”
Police said they were “not taking for granted that this was a lone wolf attack”.
Law enforcement also said during a news conference this morning that there were suspicious packages around where the gunman was.
A body with a rifle beside it was visible to members of the public on the roof of a building near the rally after the attack.
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‘The guy… he looks dead’
Investigators said earlier that they wouldn’t release details of the weapon used just yet.
FBI special agent Kevin Rojek said at a news conference that investigators had not yet identified a motive for the shooting.
National security analyst Frank Figliuzzi, explaining what will be happening as part of the investigation, told NBC that the “full panoply of the FBI will be involved”.
He said that “more immediately, all of the social media and computer devices of this shooter, all the interviews of his co-workers, family, neighbours – all of that”.
“His entire life history will be reconstructed rather rapidly and the goal here will be to see was anyone else involved, is this part of a larger conspiracy? Was there anything that could’ve been done to head this off or intervene?” he added.
“They’ll be looking at his weapon, where it came from, was it purchased legally or not? Was he trained as a sniper ever, in any profession that he may have held? And of course, what was his motive?”
Early on Sunday, the airspace over Bethel Park in Pennsylvania – Crooks’ hometown – was closed “immediately” for security reasons.