The suspect accused of killing a police officer outside a Montreal hotel had a manifesto that links him to an online community of frustrated men who talk about attacks against people who have sex, an official familiar with the matter confirmed Tuesday.The suspect armed with a long gun opened fire Monday before officers returned fire, killing him, police said. A civilian also died but it wasn’t immediately clear who fired that shot.The official, speaking on condition of anonymity as they were not authorized to speak publicly about the case, said the manifesto links the suspect to the “involuntary celibate” or “incel” ideology, a mostly online group of people, primarily men, who believe society unjustly denies them sexual or romantic attention.Police have not publicly identified the suspect.Police identified the officer killed as Constable Mohamed Lamine Benredouan, 34. He had been with the force since 2021.The manifesto prompted a warning to police forces across Canada about the possibility of copycat attacks against police officers.A police spokesperson in British Columbia said forces across that province were warned after the shooting.Staff Sgt. Lindsey Houghton with the Surrey Police Service said the information was issued Monday afternoon by an intelligence-sharing unit operating out of the Royal Canadian Mounted Police British Columbia headquarters.Quebec Domestic Security Minister Ian Lafrenière said he would refrain from commenting on details about the suspect’s identity and motives since the matter is under investigation by an independent police watchdog, which investigates injuries and deaths involving police.Montreal Mayor Soraya Martinez Ferrada said she couldn’t comment on specifics of the case but said it is important to be vigilant when there is so much hate on social media. “A lot of people are being recruited, young people. They are not on the street, they are in a difference space, which is much harder to control. That’s something that we’re going to have to be working on with the Montreal police in the future,” she saidA man who used a van to kill 10 pedestrians in Toronto in 2018 was found guilty in 2021 a case that drew attention to the online world of sexual loneliness, rage and misogyny. Alek Minassian was found guilty of 10 counts of first-degree murder and 16 counts of attempted murder.