Trump shooter failed to make school rifle team

More details are emerging of Thomas Crooks, 20, the man who attempted to assassinate Donald Trump.

Crooks lived in the Pittsburgh suburb of Bethel Park, about an hour's drive south of the Trump rally where law enforcement officials say he fired at the former president.

Crooks graduated from Bethel Park High School in 2022, according to a local media report and a video of the school's graduation ceremony.

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Jason Kohler, 21, who went to the same high school, told CNN that Crooks was bullied by other students and seemed to be a loner.

Crooks had "no facial expression" when he walked through the school hallways, Kohler said.

"He wasn't, like, with the clique, so he always had, I guess, a target on his back."

Other students mocked him for the way he dressed, such as in hunting outfits, Kohler said.

Another former student at the school, Sarah D'Angelo, remembered Crooks as "a quiet kid, not obviously political or violent in any way".

She said the only time he spoke with her was when their class was waiting for their graduation ceremony to start.

A third classmate, who asked not to be named, said that Crooks was very smart, took honours classes, and was shy.

She said that he had a group of friends who were fairly conservative, some of whom would wear Trump hats.

"There was definitely chatter about him just looking a little different," the classmate said of Crooks.

"Almost a retro nerd vibe."

Crooks tried out for the school's rifle team but was turned away because he was a bad shooter, Frederick Mach, a current captain of the team who was a few years behind Crooks at the school, said.

In Bethel Park, authorities blocked off streets around his home as a search was launched.

When reached by CNN, Crooks' father, Matthew Crooks, said he was trying to figure out "what the hell is going on" but would "wait until I talk to law enforcement" before speaking about his son.

Records show he was registered as a Republican voter in Pennsylvania, but federal campaign finance reports also show he gave $US15 ($22) to a progressive political action committee on January 20, 2021, the day President Joe Biden was sworn into office.

This year's presidential election would have been the first he was old enough to vote in.

The FBI has not yet identified the shooter's ideology, but they are combing through his social media feeds and weapons.

So far, they have not found any threatening writing or social media posts.

They have received more than 2000 tips.

Crooks is so far believed to have acted alone and was not previously on FBI's radar.

FBI Deputy Director Paul Abbate says threatening online rhetoric has been "ticking up" since the attempted assassination.

He says people are going online to pose as the shooter, who was killed by the US Secret Service.

Speaking at a press conference earlier, FBI Deputy Commissioner of Operations Lieutenant Colonel George Bivens would not guarantee that the gunman acted alone.

"I think it's too early to say that. We have one shooter tentatively identified, but we're not stopping there," he told reporters.

"We are absolutely not taking for granted that this was a lone wolf attack and so we would be looking at additional information that could point us to anyone else that may have had a hand in this.

"We're following up on a lot of information. It will be some time until we can conclusively say or answer that question."