Clifford Robert Olson Jr. was born on 1 January 1940 in Canada. Public accounts describe him as having a troubled early life and a long history of criminal activity before his killings. Olson spent much of his adult life in and out of prison, with convictions for fraud, theft, and other offenses.

In 1976, while serving a prison sentence for con artistry, Olson acted as an informant against a fellow inmate, securing favorable terms for himself. He later claimed that conversations with this inmate influenced his sexual interest in children and homicidal impulses. By the time he was released, Olson had already developed a reputation as a manipulative and cunning criminal.

Olson’s killing spree began on 17 November 1980, when he abducted 12-year-old Christine Weller from Surrey, British Columbia. Her body was found on 25 December; she had been strangled with a belt and stabbed repeatedly. Over the following months in 1981, Olson murdered ten more victims, aged between 9 and 18, across British Columbia. His methods included sexual assault, strangulation, stabbing, and bludgeoning.

Notable victims include 13-year-old Colleen Marian Daignault, who vanished on 16 April 1981; 16-year-old Daryn Todd Johnsrude, abducted on 22 April; and 16-year-old Sandra Wolfsteiner, murdered on 19 May 1981. In June, he killed 13-year-old Ada Anita Court. July 1981 saw a rapid escalation, with six murders in less than a month, including nine-year-old Simon Partington, 14-year-old Judy Kozma, 15-year-old Raymond King II, 18-year-old German tourist Sigrun Arnd, 15-year-old Terri Lyn Carson, and 17-year-old Louise Chartrand.

Olson was arrested on 12 August 1981, initially for attempting to abduct two girls. By 25 August, he had been charged with the murder of Judy Kozma. He negotiated a highly controversial plea bargain with the Royal Canadian Mounted Police: in exchange for C$10,000 per victim (paid to a trust for his wife and infant child), Olson would confess to 11 murders and lead authorities to the unrecovered bodies. The final victim’s location was revealed without payment.

On 14 January 1982, Olson pleaded guilty to 11 counts of murder and received 11 concurrent life sentences. He was incarcerated at Canada’s Special Handling Unit in Sainte-Anne-des-Plaines, Quebec. Psychiatric evaluations scored him 38/40 on the Psychopathy Checklist, marking him as an extreme psychopath.

Olson’s crimes prompted public outrage and calls for reinstating the death penalty. In 1983, a private member’s bill sought to have him executed but was ruled unconstitutional as a bill of attainder.

He repeatedly applied for parole despite his crimes, including under Canada’s “faint hope clause” in 1997, and again in 2006 and 2010; all were denied. His hearings were marked by bizarre claims, including that he had been granted U.S. clemency for aiding in September 11 investigations.

In 2010, controversy erupted when it was revealed that Olson was receiving Canada’s Old Age Security pension and Guaranteed Income Supplement while incarcerated, prompting legislative changes to stop prisoner benefits.

In September 2011, Olson was diagnosed with terminal cancer and transferred to a hospital in Laval, Quebec. He died on 30 September 2011 at age 71.