A man suspected of killing 10 people in Buffalo, New York, on Saturday appeared to target Black Americans, in what authorities called “racially motived violent extremism.”

The mass shooting killed mostly Black people and the FBI was investigating the attack as a hate crime.

In an alleged manifesto posted online before the attack, Payton Gendron, 18, also directed intense hatred at Jews, expressed support for Nazism and subscribed to the antisemitic and racist Great Replacement conspiracy theory, which says Jews are plotting to replace white Americans with non-whites.

The 180-page manifesto circulating online included the alleged shooter’s name, described the attack plans and matched statements from law enforcement.

Law enforcement officials who spoke with the Associated Press identified the alleged Buffalo shooter as Gendron, from the central New York town of Conklin, around a three and a half hour drive from Buffalo.

The manifesto attributed to Gendron was rooted in the white supremacist Great Replacement conspiracy theory, which says Jews are responsible for non-white immigration, and that non-whites will overwhelm and wipe out the white race.

Robert Bowers, who killed 11 people at Pittsburgh’s Tree of Life Synagogue in 2018, also cited the conspiracy theory before his attack. The white supremacist who killed one worshiper at a synagogue in Poway, California, said Jews were responsible for the genocide of “white Europeans.”

The author of Saturday’s manifesto wrote that the shooting was meant to kill and intimidate non-whites and spread his ideas. He said he was mainly inspired by the shooter who killed 51 people at two mosques in Christchurch, New Zealand, in 2019. He also named the Poway attacker, Bowers and other white supremacist mass shooters.

Gendron’s alleged manifesto closely resembled a document posted by the New Zealand shooter, and in some cases appeared to duplicate it, the ADL said.

He said he was acting alone, not affiliated with any particular group, and had been radicalized online starting in 2020. The author explicitly endorsed neo-Nazism, white supremacy and fascism in the document.

He said he had targeted Black people, but that Jews were “the biggest problem.”

He said Black Americans were killing white people and taking public funding, and Jews were responsible, and that although he was targeting Black Americans, Jews “can be dealt with in time.”

In the manifesto, Gendron allegedly called for a war between Jews and non-Jews.

“The real war I’m advocating for is the gentiles vs the Jews. We outnumber them 100x, and they are not strong by themselves,” he wrote.

“By their Jewish ways, they turn us against each other. When you realize this you will know that the Jews are the biggest problem the Western world has ever had,” the manifesto said. “They must be called out and killed.”

“I wish all JEWS to HELL! Go back to hell where you came from DEMON!” he wrote.

He also wrote that he was inspired to stream his attack online by another shooting that was broadcast on the platform Twitch for about 35 minutes, in a reference to the 2019 Halle Synagogue shooting in Germany, according to the ADL.

The manifesto includes lengthy passages describing the author’s views about Jewish history, genetics and beliefs, and denouncing Jewish religious texts.

“The Jews are responsible for many problems that we in the western world face today,” he wrote, saying Jews mainly used control of the media to spread propaganda. “For our self-preservation, the Jews must be removed from our Western civilizations, in any way possible.”

The advocacy group StopAntisemitism, which flagged some of the anti-Jewish content in the manifesto, said, “Once again the hatred manifested towards Jews never ends with Jews but nearly always extends to other minorities. Our thoughts and prayers are with the victims’ families.”

Other Jewish groups expressed shock and horror over the shooting, with the Jewish Federations of North America saying, “We must all stand together to defeat the vile hatred of racism.”

The shooter opened fire on shoppers at a Tops Friendly Market, a supermarket chain, on Saturday afternoon, starting in the parking lot, then going inside.

After the attack, police officials said the gunman had worn body armor and military-style clothing and streamed the shooting via a camera affixed to his helmet.

He wounded three people in addition to the 10 fatalities.