Federal investigators were still struggling Monday to determine a possible motive for would-be Donald Trump assassin Thomas Matthews Crooks after a former high school classmate described him as "definitely conservative."
It "makes me wonder why he would carry out an assassination attempt on the conservative candidate," Max Smith, who shared an American history class with Crooks two years ago, told the Philadelphia Inquirer.
A bullet fired by the 20-year-old shooter, a registered Republican and member of a gun club, grazed Trump's right ear that spattered his face with blood as he began a campaign rally speech Saturday.

Crooks also killed a spectator and critically wounded two others Saturday as he fired from a rooftop outside an outdoor arena in a Pennsylvania park.
More on Thomas Matthew CrooksThomas Matthew Crooks is shown sitting at a desk in a scene from a 2022 Black Rock promotional ad that included a number of unpaid students from Crooks' Bethel Park High School. The ad has been pulled and provided to FBI investigators, the company said.(Photo : Screen shot/YouTube)Probers said Sunday they had not yet located any social media posts or other writings indicating an ideology or political position that might explain Crooks' actions.
The gunman was killed on the scene and an AR-style assault rifle was recovered next to him.
Crooks had purchased 50 rounds of ammunitions at a gun store near the campaign rally in Butler, Pennsylvania, just hours before the event, a law enforcement source told CNN. Investigators later also found explosive devices in his car and home.
Crooks, who worked as a dietician at a nursing home in the Pittsburgh suburb of Bethel Park where he lived, "definitely was conservative," former classmate Smith told the Inquirer. 

Smith shared an American history class with Crooks at Bethel Park High School, where the future shooter received a $500 math and science award at graduation.
Smith recounted that when the teacher instructed students for mock debates to stand on one side of the classroom or the other to demonstrate where they stood on a political issue Crooks was invariably on the conservative side.
"The majority of the class were on the liberal side, but Tom, no matter what, always stood his ground on the conservative side," Smith said.

"That's still the picture I have of him. Just standing alone on one side while the rest of the class was on the other," he added.
Another classmate told the Pittsburgh Tribune-Review that Crooks, who sometimes came to school in hunting clothes, was horribly bullied.
"He was bullied almost every day," said David Kohler. "He was just an outcast, and you know how kids are nowadays." 
Money managing firm Black Rock revealed Sunday that Crooks appears in a promotional ad for the company in 2022.

Crooks was one of several unpaid students in the ad, which also included a teacher, from his school. The ad has been pulled from distribution and provided to the FBI, a Black Rock spokesman told Bloomberg. 
The company called Crooks' attack "abhorrent."
Crooks was at some point a member of the Clairton Sportsmen's Club south of Pittsburgh, which boasts 2,000 members and several shooting ranges, including one for high-powered rifles, the Los Angeles Times reported.
"Obviously, the club fully admonishes the senseless act of violence," attorney for the club Robert Bootay III, told the newspaper. 

FBI officials said Sunday that Crooks used his father's assault rifle in the attack. They believe the firearm was legally obtained by the dad.
Crooks' father, Matthew Crooks, told CNN he was talking to law enforcement authorities and wouldn't comment on his son until he could "figure out what the hell is going on."
Crooks' family was cooperating with the investigation, officials said.