CONKLIN, N.Y. (AP) — In the waning days of Payton Gendron’s COVID-19-altered senior year at Susquehanna Valley High School, he logged on to a virtual learning program in economics class that asked: “What do you plan to do when you retire?”

“Murder-suicide,” Gendron typed.

Despite his protests that it was all a joke, the bespectacled 17-year-old who had long been viewed by classmates as a loner with good grades was questioned by state police over the possible threat and then taken into custody and to a hospital for a psychiatric evaluation under a state mental health law.

But a day and a half later, he was released. And two weeks after that, he was allowed to participate in graduation festivities, including riding in the senior parade, where he was photographed atop a convertible driven by his father and festooned with yellow-and-blue balloons and signs reading, “Congratulations” and “Payton Gendron.”

That account of Gendron’s brush with the law last spring, according to authorities and other people familiar with what happened, emphasized the same point school officials made in a message to parents at the time: An investigation found no specific, credible threat against the school or any individual from that sign of trouble.

That same young white man bought a Bushmaster XM-15 rifle, traveled three hours to Buffalo and went on what authorities say was a racist, livestreamed shooting rampage Saturday in a crowded supermarket that left 10 Black people dead.

Gendron, now 18, was arraigned on a state murder charge over the weekend and a court-appointed public defender entered a not guilty plea on his behalf. He remained jailed under suicide watch as federal prosecutors contemplate hate-crime charges.

Even as the FBI swarmed the home where Gendron lived with his parents and two younger brothers, neighbors and classmates in this community of 5,000 near the New York-Pennsylvania line say they saw nothing of the kind of racist rhetoric seen in a 180-page online diatribe, purportedly written by Gendron, in which he describes in minute detail how he researched ZIP codes with the highest concentrations of Black people, surveilled the Tops supermarket in Buffalo, and carried out the assault to terrorize all nonwhite, non-Christian people into leaving the country.

Classmates described Gendron as a quiet, studious boy who got high marks but seemed out of place in recent years, turning to online streaming games, a fascination with guns and ways to grab attention from his peers.

When school partially opened again in 2020 after COVID-19-related shutdowns, Gendron showed up covered head to toe in a hazmat suit. Classmate Matthew Casado said he didn’t think the stunt — he called it “a harmless joke” — went down well with other students.

“Most people didn’t associate with him,” he said. “They didn’t want to be known as friends with a kid who was socially awkward and nerdy.”

Gendron excelled in sciences, once earning top marks in a state chemistry competition. But he was known for keeping to himself and not talking much. And when he did talk, it was about isolation, rejection and desperation.

“He talked about how he didn’t like school because he didn’t have friends. He would say he was lonely,” said Casado, who graduated with Gendron last year.

At one point last winter, Gendron’s mother called Casado’s mother with a request: Please have Matthew call Payton because he had no friends and needed to talk.

The two boys ended up going to flea markets together, watching YouTube videos and shooting guns on nearby state land over the next few months.

Some neighbors had a similar view, seeing the family as happy and prosperous, with both Paul Gendron and his wife, Pamela, holding stable jobs as civil engineers with the New York State Department of Transportation, earning nearly $200,000 combined, according to online records.

Dozens of their Facebook posts over the years show the parents and their three boys — often dressed in matching outfits — enjoying amusement park vacations, going on boat trips and camping trips, shooting laser tag guns and opening presents on Christmas morning.

Carl Lobdell, a family friend who first met Gendron on a camping vacation a dozen years ago, said he was shocked that Payton was identified as the suspect in the mass shooting.

“When I heard about the shooting … I just cried,” he said.

One of Gendron’s lawyers, Daniel DuBois, said Tuesday he had no comment. The family did not respond to a request for comment over the weekend. No one answered the door Monday at the family home, surrounded by a neat, spacious lawn. Near the front door was a tiny right hand pressed in concrete with a heart symbol and the words, “PAYTON 2008.”

One parent of a Susquehanna Valley High student said she was furious that the student who was investigated for making the threat last year — whom she later discovered was Gendron — was still allowed to participate in all graduation activities. The woman asked not to be identified because she feared harassment.

According to a recording of a conference call of federal and local law enforcement officials Monday that was obtained by The Associated Press, Buffalo Police Commissioner Joseph Gramaglia said Gendron’s comments he made in school in June 2021 were “generalized statements” and not targeted at anyone in particular or at a specific location, which is why no criminal charges were filed. He said the state police “did everything within the confines of the law.”

Gendron enrolled at Broome County Community College and later dropped out. The school wouldn’t say why. And according to online writings attributed to him, he began planning his assault on the Buffalo supermarket beginning at least in November, saying he was inculcated into his racist views online.

“I was never diagnosed with a mental disability or disorder, and I believe to be perfectly sane,” according to one passage.

A new, 589-page document of online diary postings emerged Monday that authorities have attributed to Gendron. In it, he describes his preparations for the Buffalo supermarket shooting in detail, writing at one point that he considered attacking a predominantly Black elementary school instead. He also recounted how he chased down a neighborhood cat, stabbed and decapitated it with a hatchet, took a picture and then buried it in the backyard.

Some of its passages also aligned with the account AP’s sources gave of his high school threat investigation.

“Another bad experience was when I had to go to a hospitals ER because I said the word’s ‘murder/suicide’ to an online paper in economics class,” said one entry. “I got out of it because I stuck with the story that I was getting out of class and I just stupidly wrote that down. That is the reason I believe I am still able to purchase guns.”

“It was not a joke, I wrote that down because that’s what I was planning to do.”