The man accused of attacking a synagogue in Germany broadcast his rampage on the Twitch live-streaming video platform.
Speaking in English, the man called himself “anon” and said he was a Holocaust denier.
“Feminism is the cause of declining birth rates in the West, which acts as a scapegoat for mass immigration, and the root of all these problems is the Jew,” he continued, while filming himself in a car before starting the attack.
The footage was verified by the International Centre for the Study of Radicalisation (ICSR) at King’s College London after being shared online.
Police said at least two people had been killed in Halle – outside the synagogue and at a nearby kebab shop – and a separate shooting was reported in a nearby town later on Wednesday.
Witnesses reported the gunman was wearing a helmet mounted with a camera and military-style clothing.
The footage, which has since been removed from the Twitch website – which focuses on video game streaming – appeared to be filmed by a head-mounted camera and showed the shooting from the attacker’s perspective
A similar broadcast was made by the Christchurch shooter, who used Facebook Live, and posted a “manifesto” espousing a theory that white people are being eradicated from Western nations on the 8chan image board.
The attack inspired copycat terrorists around the world, including in the UK, Norway and the American cities of El Paso and Poway – where a synagogue was attacked.
On the 4chan website, some posters were comparing the Halle shooter to “Saint [Brenton] Tarrant”, while another wrote: “Kill society, one lone gunman at a time. F***, I’m lovin it.”
Others ridiculed the shooter, who called himself a “loser” repeatedly in the video, for failing to kill more victims.
German police said they had arrested one person following the attack in Halle, but it was unclear whether other suspects could be at large.
The country’s federal public prosecutor has taken over the investigation into the case – a move commonly seen for suspected terror attacks.
Before the Twitch footage emerged, a spokesperson told The Independent they were looking into potential ideological motivations including far-right extremism, but had not confirmed the background to the shootings.
One victim’s body was in the street outside the synagogue, while another victim was said to have been shot at a nearby Turkish kebab shop.
Officials at the Uniklinikums Halle hospital said it was treating two more people for gunshot injuries, including a victim undergoing surgery.
The Halle incident started at around noon local time (11am BST) on Humboldtstrasse, which houses a synagogue and Jewish cemetery.
Witnesses reported that a man had attempted to break through the door of the synagogue and then shot a female passerby.
An eyewitness told reporters at the scene that he heard an explosion at the Jewish cemetery, and that he saw the attacker use both a shotgun and machine gun.
He described the gunman being “dressed like a police officer” with protective clothing and a helmet, and said he fled in a Volkswagen Golf.
The Bild newspaper reported that the attacker used a submachine gun in the assault, and threw a hand grenade into the cemetery.
The attack came during Yom Kippur, a Jewish religious festival that sees observers fast and pray to atone for sins.
A spokesperson for the local Jewish community told Der Spiegel that up to 80 worshippers were inside the synagogue at the time, but security measures at the synagogue’s entrance “withstood the attack”.
Local reports said a second victim was killed outside a kebab shop around 600m away.
Conrad Roessler told N-TV the man threw something that looked like a grenade, which bounced off the doorframe, before opening fire.
“All the customers next to me ran, of course I did too – I think there were five or six of us in there,” he said. “The man behind me probably died.”
Mr Roessler said he hid in a toilet as other customers attempted to flee out of the back of the takeaway, adding: “I locked myself quietly in this toilet, and wrote to my family that I love them, and waited for something to happen.”
A separate shooting was later reported in the town of Landsberg, around a 20 minute drive from Halle.
Anja Werner, the mayor of Landsberg, later said two suspects had hijacked a car and were on a motorway that leads to Munich.