Swedish commission blames conviction of fake serial killer on 'groupthink'

He was Sweden's most notorious serial killer. Sture Bergwall, formerly known as Thomas Quick, confessed to more than 30 murders in the 1990s, including gruesome admissions that he dismembered and cannibalised a number of his victims. He was charged with eight killings and sentenced to an institution for the criminally insane. But he lied about it all.

It's been called the country's "worst miscarriage of justice." But, on Friday, a commission of lawyers set up to examine the Bergwall case found no evidence of systemic problems in the justice system. They instead placed the blame on "groupthink."

"He was convicted without any evidence at all,"  says Jenny Küttim, a journalist and researcher who was part of an investigative report that revealed that Bergwall's confessions were false. "He was convicted on his own confession to these crimes. All of these confessions came up in therapy which he had when he was institutionalized."

Along the way, all those involved in the murder investigations simply took Bergwall at his word, Küttim tells As It Happens host Carol Off.

"This investigation was a mix of ward staff and the police," she continues. "He developed these stories inside therapy and they grew stronger over the years.

"He got information from the newspaper or through the police interrogator that he grew a strong bond with. He confessed over a period of nine years. It was the same group of people [during this time] who were leading these police investigations. That's what the commission today is pointing at... it's a phenomenon of 'groupthink.'"

Bergwall suffered from mental illness, was a compulsive liar, and a drug addict.

"I think he confessed because he wanted to be a heavier criminal," Küttim theorizes. "He wanted to get some rank by confessing to murder. Then, he realized that he could get tranquilizers."

During the investigation, he was supplied a steady stream benzodiazepines, a class of potent tranquillizers.

"Obviously he'd confess to anything just to get a hold of a pill," she adds. "[And eventually], he actually believed that he killed people, creating false memories."

His legal defense did not challenge the convictions, at Bergwall's request, she says. 

Bergwall admitted to lying about his confessions back in 2008. His last conviction was overturned in 2013. He is now free, sober, and lives on his own in northern Sweden. Küttim has met him several times.

"Looking back at this story, obviously he has a tremendous responsibility [confessing to] these heinous crimes," she says. "He was a part of this sect, or 'groupthink,' but he is actually the only one taking responsibility."