Gunman who killed 10 in NY supermarket attack was on authorities' radar

New York authorities on Sunday were investigating how a white 18-year-old, who the governor said had been on the radar of authorities since high school, was able to shoot 10 people to death in a black neighbourhood grocery store.

The suspect, Payton Gendron, surrendered to police on Saturday at the Buffalo, New York, store after what authorities called an act of "racially motivated violent extremism." He apparently publicised a racist manifesto on the internet.

The Buffalo shooting follows other racially motivated mass murders in recent years, including a Pittsburgh synagogue attack that left 11 dead in October 2018, and the Atlanta spa shootings in March 2021 in which a white man killed eight people, targeting Asians.

President Joe Biden urged unity on Sunday to address the “hate that remains a stain on the soul of America” while state officials pleaded for federal action to end the ”uniquely American phenomenon” of mass shootings.

Addressing an annual law enforcement ceremony at the US Capitol, Mr Biden said he and first lady Jill Biden prayed for those who were shot “by a lone gunman, armed with weapons of war and hate-filled soul,” and their families.

Authorities said Mr Gendron drove to Buffalo from his home several hours away to launch the afternoon attack, which he broadcast in real time on social media platform Twitch, a live video service owned by Amazon.com.

New York Governor Kathy Hochul said the firearm used in the killings was legally purchased but had been illegally modified with a high-capacity magazine.

Eleven people struck by gunfire were black and two were white, officials said. The racial breakdown of the dead was not made clear.

Federal agents have interviewed Mr Gendron's parents, a police official told The Associated Press on Sunday.

A manifesto that was posted online is being assessed by the authorities for authenticity.

The 180-page document described a plot in detail and identified Mr Gendron by name as the gunman, the official said.

A preliminary investigation found Mr Gendron had repeatedly visited sites espousing white supremacist ideologies and race-based conspiracy theories and extensively researched the 2019 mosque shootings in Christchurch, New Zealand, and the man who killed dozens at a summer camp in Norway in 2011, the official said.

His parents were co-operating with investigators, the official told AP.

Mr Gendron had travelled about 320 kilometres from his home in Conklin, New York, to Buffalo.

Investigators believe he had specifically researched the demographics of the population around the Tops Friendly Market and had been searching for communities with a high number of African-American residents, the official said. The grocery store is in a predominantly black neighbourhood.

“It’s just too much. I’m trying to bear witness but it’s just too much. You can’t even go to the damn store in peace,” Buffalo resident Yvonne Woodard told AP. “It’s just crazy.”

In a Sunday interview with ABC, Buffalo Police Commissioner Joseph Gramaglia said that Mr Gendron had been in town “at least the day before”.

“It seems that he had come here to scope out the area, to do a little reconnaissance work on the area before he carried out his just evil, sickening act,” Mr Gramaglia said.

Screenshots purporting to be from the Twitch broadcast appear to show a racial epithet scrawled on the rifle used in the attack, as well as the number 14, which could be a reference to a white supremacist slogan.

Among the dead was security guard Aaron Salter, a retired Buffalo police officer. He had fired shots at Mr Gendron, Mr Gramaglia said on Saturday. A bullet hit the gunman’s armour, but had no effect. Mr Gendron then killed Salter, before hunting more victims.

“He cared about the community. He looked after the store,” Yvette Mack, who had shopped at Tops earlier on Saturday, said of Salter. “He did a good job, you know. He was very nice and respectable.”

Ms Hochul, a Buffalo native, called for the tech industry to take responsibility for their role in propagating hate speech in a Sunday interview with ABC.

“The CEOs of those companies need to be held accountable and assure all of us that they’re taking every step humanly possible to be able to monitor this information. How these depraved ideas are fermenting on social media – it’s spreading like a virus now,” she said, adding that a lack of oversight could lead to others emulating the shooter.

The mass shooting further unsettled a nation wracked with racial tension, gun violence and a spate of hate crimes. A day before, police in Dallas had said they were investigating shootings in the city’s Koreatown as hate crimes.

Last month, a mass shooting wounded 10 on a subway train as it travelled through Brooklyn.

When confronted by police in the store’s vestibule, Mr Gendron put a rifle to his neck but was convinced to drop it.

He appeared before a judge later on Saturday, wearing a paper gown.

- With agencies.