PITTSBURGH (TNS) — If Thomas Matthew Crooks meticulously researched and planned his path to infamy in the days and weeks before he army-crawled across the sloped metal roof near the Butler Farm Show grounds, he left behind few if any red flags.

The mystery only deepened after investigators briefed Senate Republicans this week. Federal authorities could answer few questions about the 20-year-old who tried to kill former President Donald Trump, nor could they give any inkling as to why the Bethel Park High School grad opened fire Saturday.

Crooks used his cellphone to search for photos of Trump and look up the dates of his appearances, authorities told the senators, according to the New York Times. But he also searched for photos of President Joe Biden and sought out the dates of the Democratic National Convention. He searched “major depressive disorder,” too.

As federal investigators combed through every inch of Crooks’ two decades of life, those who knew him prior to Saturday remembered him as smart and shy, if not a bit of a loner. They recalled nothing that might foretell the makings of a political assassin.

“I remember him being very intelligent and kind, but he was definitely a quiet kid,” former classmate Anna Counihan said.

She called it heart-wrenching to hear that the boy with whom she shared a homeroom all throughout high school had been shot and killed by Secret Service snipers after he opened fire on Trump and the crowd gathered to hear him speak.

The two were acquaintances, she said, but worked together in class sometimes in high school. He was “on the shy side,” but “he was never sketchy or anything.” Counihan said she never heard Crooks talk politics, but he projected a conservative air. She said she believed he was a Republican “just by how he presented himself.”

Max Shrager, 20, a current student at Duquesne University, first met Crooks in sixth grade reading class. They knew each other all through middle school and high school, and were “never really close,” but they did share mutual friends.

“It genuinely breaks my heart, for the parents even, to see these kids that are speaking on the news and stuff, saying that he was nicknamed the school shooter years prior … because it’s absolutely not true at all,” he said. “I don’t think that anybody would have thought anything like that of him. He never gave off that kind of vibe.”

He described Crooks as a “very polite, very respectful” kid who kept to himself and was very good with computers.

“He seemed like such a normal person,” Kylie Katilius said.

She knew Crooks for most her life — they lived near one another and rode the same bus to school. Katilius, now a senior at the University of Pittsburgh, recalled Crooks’ abysmal tryout for their Bethel Park’s rife team.

The range was seven lanes, about 20 feet wide. When it was his turn to shoot, she said, Crooks fired off a wild shot that went nearly to the other side of the range.

“If he was on lane seven, he was shooting all the way over on lane one,” she said. “Mistakes happen, but full on shooting a different wall — he had to be doing something big wrong. That’s not just a mistake, that’s deadly.”

Katilius said the coach, a stickler for safety, told Crooks he wouldn’t be allowed on the team. She said Crooks, a freshman at the time, seemed a little embarrassed.

Crooks graduated from high school in June 2022. Video footage from the ceremony shows a tall, lanky teen smiling as he accepts his diploma. By that point, he had already started classes at the Community College of Allegheny County as part of a dual-enrollment program. He graduated with an associate’s degree in engineering science in May 2024.

He appears to have made few impressions at the community college, and those who did know him described him much the same as his high school acquaintances.

“Nice and kind,” said Carlos, a faculty member at CCAC’s West Mifflin campus who only wanted to be identified by his first name. Though he never had Crooks in class, he’d helped him use a 3D printer for one of his class projects.

“He was a good student,” he said.

Crooks planned to enroll at Robert Morris University this fall, university officials said.

Crooks was a dietary aid at a skilled nursing facility not far from his home. A co-worker who spoke to CNN called him “the sweetest guy.”

The co-worker said they’d worked together last week trying to find an easier way for the nursing home residents to open ranch dressing packets served with meals. It was an act indicative of Crooks’ caring nature, she said.

“These stupid ranch packets in the kitchen — no one can ever open them,” the co-worker, who also went to high school with Crooks, told the news network. “Earlier this week he was helping me with a bunch of sick old ladies [to] put ranch on their salads.”

She said he never talked politics and didn’t seem to be “a radical.”

“He was a really, really good person that did a really bad thing,” she said, “and I just wish I knew why.”

Federal investigators, too, are looking for those answers — so far, in vain.

Investigators said in the briefing that although his search history showed he was broadly interested in powerful and famous people, it appeared to be without any obvious ideological or partisan pattern. Really, authorities said, it seemed the registered Republican had no strong political views either way, the Times reported.

That in itself was notable, authorities told the legislators, as was the absence of any political or ideological information at the Bethel Park home Crooks shared with his parents. Most who carry out acts of political violence, authorities said, tend to leave behind a discernible trail of political views.

Crooks was armed with an AR-style rifle that his father bought more than a decade ago, investigators have said. He also had improvised explosive materials in the trunk of his Hyundai Sonata, and authorities found similar materials in his Bethel Park home.

According to the Times, authorities said Crooks received multiple packages over the past several months, including some that were marked “hazardous material.” The bombs were a potentially explosive mix of fertilizer and fuel packed into two empty ammunition cans, investigators told the legislators. He had a remote receiver when he was killed — the kind used to set off fireworks displays from a distances.