Authorities believe Mr. Gendron traveled more than 200 miles from his home in Conklin, N.Y., in the state’s Southern Tier, to commit his attack, choosing the East Side of Buffalo because of its large number of Black residents.
In a lengthy rant that Mr. Gendron, who is white, is believed to have written and posted online in the days before the attack, he expressed admiration for other gunmen in racist attacks and repeated references to a white supremacist ideology known as replacement theory, which imagines a sinister scheme to “replace” white Americans with immigrants or people of color.
Mr. Gendron’s postings on Discord also indicate that he was able to sidestep a New York state statute — known as a “red flag” law — designed to bar people believed to be dangerous from possessing firearms. In 2021, Mr. Gendron had been picked up by the state police and taken for a mental health evaluation at a hospital after indicating on a school project that he wanted to commit a “murder-suicide.”
He was released, however, after telling officials he was only joking, something he said was a lie in a Discord posting.
“It was not a joke,” he wrote on Discord. “I wrote that down because that’s what I was planning to do.”
Since the Buffalo shooting, and the horror in Uvalde, lawmakers in Albany have moved to propose a series of new measures to tighten the state’s already tough gun laws, including raising the age to 21 for ownership of a semiautomatic rifle. Those bills are expected to pass the Democrat-dominated Legislature this week.
Gov. Kathy Hochul, a Democrat, had already announced a pair of executive orders related to the Buffalo attack, including one that required the State Police to seek red-flag orders from judges “whenever they have probable cause” that someone may be a danger to themselves or others. Ms. Hochul also ordered the police “to track domestic violent extremism through social media,” like the channels Mr. Gendron is believed to have used.
Susan C. Beachy contributed research.