For Thomas Crooks, the suburban Pittsburgh nursing home where he served meals and washed dishes for $16 an hour was another solitary corner of a nearly invisible life. He was polite but distant, a former co-worker said, ate lunch alone in the break room and rarely spoke with anyone.

But as western Pennsylvania geared up last week for the boisterous spectacle of hosting a rally for former President Donald Trump, Crooks approached his bosses with a request, law enforcement officials said: He wanted to take Saturday off.

He told them he had something important to do.

It was one of the few hints to emerge so far that the 20-year-old engineering sciences graduate was planning to become a political assassin. A week after Crooks opened fire at the rally and was killed by the Secret Service, his ideology and motives remain a vexing question for investigators and the people who crossed paths with him.

In dozens of interviews, former classmates, teachers and neighbors said they still could not square their memories of Crooks — an awkward, intelligent teenager who liked to tinker with computers and spent his weekends playing video games — with the image of the stringy-haired gunman at the rally, armed with his father’s AR-15-style rifle as he clambered onto a rooftop and took aim at the former president. Trump suffered an injury to his ear, and three spectators were wounded, one of them fatally.

“That’s where I’m struggling; I’ve looked at horrific pictures of an individual that I stood 6 inches away from, shaking his hand, calling on him in class,” said Xavier Harmon, who saw Crooks almost daily in the computer technology class he taught at a technical school.

Many of the young men who have attacked schools, movie theaters, supermarkets and churches in recent years deliberately or unintentionally hinted at their rage, violent fantasies or plans well before their attacks — a phenomenon that researchers call “leakage.”

Investigators have uncovered what now could be seen as concerning signs: The gunman’s phone showed that he had possibly read news stories about the teenage school shooter who killed four students at Oxford High School in Michigan. Crooks received multiple packages, including several that were marked “hazardous material,” over the past several months. He looked up “major depressive disorder” on a cellphone later found at his house.

He had also searched a bipartisan roster of political figures, including Trump, President Joe Biden and Attorney General Merrick Garland, FBI officials told members of Congress. He also looked up the dates of Trump’s July 13 rally in Butler, Pennsylvania, as well as the Democratic National Convention in Chicago.

But investigators have not found any evidence that Crooks had strong political beliefs or an ideological motivation.

Experts who study the histories of gunmen said the emerging picture of Crooks looked more like a 21st-century school shooter than a John Wilkes Booth.

“When somebody attacks a president, our gut instinct is to say, ‘That must be politically motivated,’” said James Densley, a founder of the Violence Project, which has compiled a comprehensive database of mass shootings. “What we might be seeing here is: This was somebody intent on perpetrating mass violence, and they happened to pick a political rally.”

The rally he chose was announced in early July for the Butler Farm Show grounds, just an hour’s drive from Crooks’ hometown, Bethel Park, a mostly white, middle-class suburban town of about 32,000 where Crooks spent nearly all of his life.

He was born in 2003 and grew up in a modest red brick house on a grassy, rolling road, the younger son of a politically mixed family. He attended local schools, graduating from Bethel Park High School in 2022 and from a local community college, where he received an associate degree in engineering science, in May.

Crooks was a registered Republican, though records show he also donated $15 to a progressive cause on the day of Biden’s inauguration in January 2021. Voting records show his mother is a Democrat, and his father and older sister are Libertarians.

The Trump era has brought tensions to local politics in Bethel Park, a traditionally Republican town that is now almost evenly divided. Trump beat Biden there by just 65 votes in 2020. This year, the fissures of election season are everywhere.

Some houses fly Trump flags and “Let’s Go Brandon” banners. Others have “Stronger Together” yard signs. MAGA fans in surrounding towns hold flag-waving rallies on highway bridges to provoke liberals. Last Halloween, one resident decorated his lawn with a skeleton pointing a gun at another skeleton wearing a Biden T-shirt.

But several neighbors said the Crooks family did not put out yard signs to display their politics. In fact, they said, they rarely saw the family at all.

Crooks’ parents, Matthew and Mary, are both licensed professional counselors, and interviews and business records suggest they have been working from home at least since the pandemic.

Crooks’ father worked at Community Care Behavioral Health, part of the insurance services division of the University of Pittsburgh Medical Center, connecting patients with in-network counselors, a former colleague said.

FBI investigators who searched the family’s home discovered it was cluttered and not well-cleaned, something akin to a compulsive hoarder’s house.

A neighbor said that years ago, she occasionally saw Mary Crooks — who, according to federal authorities, was visually impaired — walking home from work from the local T train station, using a cane. But she had not seen her walking around in recent years.

As a child, Crooks befriended other children in the neighborhood and would walk up the block to play in their backyard, one neighbor said. The neighbor said the young Crooks was fond of wearing polo shirts tucked into cargo shorts and remembered him as a smart, nerdy child with a penchant for math.

But the family became more insular in recent years, neighbors said. They said Crooks’ parents would wave to neighbors from their lawn and say good morning but never initiate conversations.

Kelly Little, 38, said she had never had a conversation with the family, despite living across the street from them. Her son, Liam Campbell, 17, said that he rode the bus with Crooks and noticed that he was always very reserved.

“He didn’t speak to anyone, and no one spoke to him,” he said. “He seemed like the kind of person who didn’t like to start conversations with people he didn’t know. He seemed nervous.”

It is unclear how and when he became interested in guns, but his father owned more than a dozen firearms, including the semiautomatic rifle used in the attack.

Anthony Pusateri, a member of the rifle team at Bethel Park High School from 2018 to 2020, recalled that Crooks had tried out for the team, most likely when he was a sophomore, but was a bad shot and did not make the team.

“He just didn’t shoot well enough,” Pusateri said.

He had almost no presence on social media, but the T-shirt he was wearing on the day he attacked the rally was one sold by Demolition Ranch, a popular gun-themed YouTube channel popular in the online world of guntubers, gun enthusiasts who post reviews and explanations of firearms as well as videos of themselves shooting up watermelons or ballistic dummies.

In high school, some former classmates said Crooks was aloof, kept to himself and was teased about his hygiene and body odor. They said he walked through the halls with his head down and revealed little about himself in class or on social media.

But others insisted that Crooks had not been bullied and was not isolated, and remembered him as having a small cluster of friends. They said he never raised any concerns for them. Jim Knapp, his former guidance counselor, said that Crooks had sat by himself at lunch and played on his phone but that he was content to do so.

School officials said Crooks did not have any disciplinary problems in high school and was sent to detention once, in eighth grade, for chewing gum, according to school records released Friday. He rarely missed a day of school, and teachers noted that he participated in class and was interested in learning.

Knapp said he had to call Matthew and Mary Crooks a few times to discuss minor issues about Crooks or his older sister, and he said the parents seemed polite, responsive and engaged. But he said the family was insular.

“They stuck to themselves,” he said.

Most afternoons during his sophomore and junior years of high school, Crooks would catch a bus to attend the computer technology program at the Steel Center for Career and Technical Education. The school draws hundreds of students from southeastern Allegheny County who take classes in auto repair, cosmetology and other job-focused areas.

If he was often alone at his regular high school, he seemed more at ease in his classes at Steel. Crooks engaged with his classmates and “wanted to be part of the group,” Harmon said.

He would crack unfunny jokes, and his laughter would prompt other students to laugh, Harmon said. A shaky cellphone video from his time there shows Crooks making crude jokes about his height and sexual endowment while another student laughs and holds up two fingers behind his head.

“A lot of them didn’t feel like they were accepted among their peers, so computer technology was their place they called home,” Harmon said.

Harmon said Crooks “set the standard” for academics. He rarely scored low on tests and performed so well during impromptu quiz games that Harmon said he changed the rules to allow other students a chance to answer.

In an autobiographical statement Crooks wrote for his induction into the National Technical Honor Society in spring 2021 as a high school junior, Crooks said he had a lifelong interest in building things and that he and his father had built a computer together in 2017.

His interests, Crooks wrote, “are highly varied, and include computer technology, engineering, history and economics.”

He often finished his work before other students and would sometimes play computer games during idle moments.

“He’d go in the back, grab a computer, grab a screwdriver kit and start breaking it down, clean the pieces of stuff and then put it back together,” Harmon said.

He recalled giving Crooks what he called an ironic nickname — “Muscles,” because he was so skinny. He said Crooks rolled with it.

Crooks, he said, didn’t weigh in on politics, even when some of his other classmates did, and preferred to talk about the latest technology news or even cryptocurrency. Even when he asked the class to share about their weekends, Harmon added, Crooks usually didn’t have much to say.

“Tom always had something like, ‘Well, I sat in my bedroom, and I was gaming. I was on my computer. I didn’t do much this weekend, but I still had fun,’” Harmon said. “Other than his drive for academics, Tom was simple.”

He graduated with a cumulative GPA of 4.047, according to school records. His class of about 300 students hooted and cheered as their friends crossed the stage together, in person and unmasked after years of pandemic disruptions. When Crooks’ name was called, he received a smattering of polite applause as he accepted his diploma.

He did not go far after graduation. After community college, he planned to enroll this fall at Robert Morris University, just outside Pittsburgh.

But as the summer began, it appears that his plans began to change.

On July 7, six days before the political rally, Crooks may have cased the site of the planned event. On Friday, the day before the rally, he spent much of the day at the gun range, his parents told investigators. On Saturday, he went to Home Depot at 9:30 a.m. to buy a ladder, purchased 50 rounds of ammunition later in the afternoon and drove to the rally. In the Hyundai Sonata he drove to the rally, investigators said, he left behind two rudimentary explosive devices, several magazines for the rifle he used, a bulletproof vest and a small drone.

The nursing home said it was shocked to learn the news. Crooks had told them he would be back at work Sunday.

The New York Times News Service