On May 14, 2022, a mass shooting occurred[14][15] in Buffalo, New York, United States, at a Tops Friendly Markets supermarket in the East Side neighborhood.

[22] Gendron is reported to have written a manifesto describing himself as an ethno-nationalist and a supporter of White supremacy who is motivated to commit acts of political violence.

[21] Around March 19, 2024, a New York state judge ruled Reddit and YouTube must face lawsuits in connection with the mass shooting over accusations that they played a role in the radicalization of the shooter.

[38] In addition to Salter, the people fatally shot were Celestine Chaney, 65; Roberta A. Drury, 32; Andre Mackneil, 53; Katherine Massey, 72; Margus D. Morrison, 52; Heyward Patterson, 67; Geraldine Talley, 62; Ruth Whitfield, 86; and Pearl Young, 77.

Bandits head coach John Tavares told the media after his team's victory that the athletes played "definitely with a heavy heart" given the circumstances.

[45] A charity softball game at Sahlen Field featuring members of the Buffalo Bills held a moment of silence prior to the event and donated a portion of the proceeds to victims' families.

[51] Stephen Belongia, the head of the local FBI office, told reporters that the agency was investigating the shooting as both a hate crime and an act of racially motivated violent extremism.

[55] According to law enforcement sources who spoke to The Buffalo News, they were investigating Gendron's alleged contact with a number of people online, including a retired federal agent, and whether these individuals had thirty minutes of advance notice of the attack yet did not notify the authorities.

[20][60][61] Gendron graduated from Susquehanna Valley High School[62] and was previously enrolled at SUNY Broome Community College in Binghamton for an engineering science program.

[76] Gendron's gun also reportedly was covered with references to White supremacist mass murderers Dylann Roof, Robert Bowers, Brenton Tarrant, and John Earnest, the acronym SYGAOWN (Stop Your Genocide Against Our White Nations),[77] far-right slang "Buck status: broken",[78] the year 2083—a reference to the manifesto of Anders Behring Breivik[79]—and a depiction of the Archangel Michael's Cross of the fascist Romanian Iron Guard.

[79][80][81] A law enforcement source told The Daily Beast that Gendron had also written on his rifle the names of one or more victims of the Waukesha Christmas parade attack.

[82] On the weapons in his car which had not been used during the shooting, he reportedly had written "White Lives Matter" and, according to CNN, "what appears to be the name of a victim of a crime committed by a Black suspect.

[91][92] The manifesto's author also expressed support for far-right mass shooters Dylann Roof, Anders Behring Breivik, and Brenton Tarrant.

[66] Thousands of chat logs were retrieved from the account's postings in a private chatroom, which were written in the form of an online diary and range from November 2021 to May 13, 2022.

[102] The chat logs indicated that the attack was originally planned to occur on March 15 so that the author could commemorate the anniversary of the Christchurch mosque shootings.

[101][106] The author considered attacking various locations, including a Walmart in Rochester, New York, and institutions with predominantly Black attendees such as churches, malls, and elementary schools.

[99] Other than the online diary, chat logs related to the attack were also retrieved from a second chatroom on Discord where members primarily discussed weapons as a dedicated topic.

[104][114] Following the shooting, the livestream footage quickly leaked to multiple other social media sites, including Facebook, Twitter, Instagram, and Reddit.

[120][11] On June 3, 2022, a filing made on behalf of one of the survivors from the attack sought a court order for the preservation of a number of items in the possession of Gendron's parents.

[121][122] The filing sought to preserve, among other things, any of his available cellphones, computers (and web browsing history), travel and school records, video game consoles, and receipts for firearms and ammunition.

The Daily Beast journalist Andy Craig has argued that beliefs "centered around the claim that there is a deliberate plot to commit to genocide against white Americans—using non-white immigration as its supposed primary means" created a "noxious brew of ideas" that animated the killer, recommending that all supporters of freedom of speech as an ideal condemn such extremist thinking.

[6] Gendron's claim of a Great Replacement has drawn increased scrutiny of Republican political and media figures who have made statements embracing or echoing the conspiracy, most prominently Fox News commentator Tucker Carlson.

"[140] However, Kate Maltby, writing for The Jewish Chronicle, drew attention to language Gendron used in his reported manifesto attacking diversity, which is similar to wording Carlson employed in one of his broadcasts.

Republicans argued that the measure duplicated already existing efforts by American law enforcement while also risking targeting individuals unfairly as political extremists.

Democrats noted the tough polarization in Congress while arguing that the Republicans failed to compromise on pragmatic changes to fight gun deaths.

[145][146] On June 7, 2022, the United States Senate Committee on the Judiciary held hearings to examine "the 'Metastasizing' Domestic Terrorism Threat After the Buffalo Attack.

[148][149] In response to this attack, as well as the Robb Elementary School shooting in Uvalde, Texas that occurred 10 days afterwards, the New York State Legislature passed laws banning semi-automatic sales to most people under 21 as well as certain types of body armor.

"[23] Hochul called for stronger federal gun violence prevention legislation, saying "What has made this so lethal, and so devastating for this community, was the high-capacity magazine that would have had to have been purchased elsewhere, that's not legal in the state of New York.

"[70][73] The attorney for one of the victims' families, Benjamin Crump, has argued that public policy changes need to take place to fight political extremist activism as a result of the shooting.

According to the coalition, "the mission is to create a historical record that will demonstrate to current and future generations a true account of the tragedy that took the lives of ten innocent people, wounded three others, and forever changed the history of our city".