HIS classmates thought he was harmless. But on the afternoon of April 23rd Alek Minassian, a 25-year-old computer programmer from Toronto, drove a van into lunchtime strollers, careering along for more than a kilometre, killing ten and injuring 14 others. His aim, apparently, was to murder women, because women would not have sex with him.

Beforehand, Mr Minassian posted a message on Facebook proclaiming: “The Incel Rebellion has already begun! We will overthrow all Chads and Stacys! All hail Supreme Gentleman Elliot Rodger!” Canadians googled furiously to find out what this might mean.

They found that “incel” is short for involuntarily celibate. Members of this movement are furious that women (sometimes referred to as “Stacys”) won’t sleep with them. They also resent “Chads” (men who find it easy to get sex). They mostly confine themselves to grumbling in online chat-rooms. Some swap alarming fantasies of “revenge” through rape. A few idolise Elliot Rodger, who slaughtered six people during a misogynistic murder spree near the campus of the University of California, Santa Barbara, before killing himself.

Mr Minassian’s victims were predominantly women, of all ages. He was arrested unharmed, after he tried to goad a police officer to shoot him in the head. Within hours, Canada’s federal public-safety minister, Ralph Goodale, declared that the attack posed no threat to national security. The Toronto police said they had no previous record of the suspect, who was charged with ten counts of murder and 13 of attempted murder.

Acquaintances of Mr Minassian said he was awkward around women and kept repeating that he was frightened of them. Perhaps because of his emotional disorders, he took seven years to complete a computing degree. He briefly enrolled in the Canadian army last year, but left two weeks into a four-month basic course, before he had been trained in weapons. Unlike the perpetrators of some recent terrorist attacks in Canada, Mr Minassian had no links with jihadism.

He is not Canada’s first woman-hating mass killer. Back in 1989, a man called Marc Lépine entered an engineering college in Montreal and shot and killed 14 women, after separating them from men, before killing himself. That prompted the government of the time to set up a national gun registry. In 2012, long guns were removed from the registry. No one knows how to stop homicidal men from hiring vans.