(AFP) — The US Justice Department announced federal hate crimes charges Tuesday against Payton Gendron, the 18-year-old who shot dead 10 African Americans at a Buffalo, New York supermarket in May.

The charges say Gendron was motivated by racist hate when, on May 14, he took a semi-automatic assault weapon to a grocery store in a largely Black neighborhood of Buffalo and killed 10 people, while wounding three others.

They said he was driven by belief in a conspiracy theory called “The Great Replacement” — that white people’s lives and communities are threatened by minorities — a view Gendron espoused in a lengthy document posted online before his attack.

“Gendron’s motive for the mass shooting was to prevent Black people from replacing white people and eliminating the white race, and to inspire others to commit similar attacks,” the charges said.

He planned his attack in detail for months, according to the charges, and he specifically targeted a heavily African-American community, mapping out the popular Tops supermarket there.

He said in his manifesto that he intended to “Kill as many Blacks as possible.”

The federal hate crime charges carry the death penalty or up to life in prison.

Attorney General Merrick Garland announced the charges on a visit to Buffalo, where he met with family members of those killed.

“Hate-fuelled acts of violence terrorize not only the individuals who are all attacked but entire communities,” Garland said.

“We fully recognize the threat that hatred and violent extremism pose to the safety of the American people and American democracy,” he said.

On June 1, Gendron was charged by New York state with domestic terrorism and ten counts of first degree murder.

© Agence France-Presse