Has AI solved mystery of Swedish PM's assassination?

A fresh analysis of the unsolved murder of Swedish prime minister Olof Palme using AI implicates a new suspect - and threatens to derail the original investigation.

Palme was walking home from the cinema with his wife when he was gunned down at point-blank range by an unknown assailant in central Stockholm in February 1986. 

In the years since, theorists have tried to pin the killing on everything from foreign interference to aggrieved arms dealers and CIA assassination.

Police eventually concluded that the real killer was 'probably' graphic designer Stig Engström, long treated as a mere witness to the assassination, who died in 2000.

But a new AI comparison of photographs of the main suspects found Engström to bear much less resemblance to the facial composite than another key witness.

Jon Jordås, Director of Documentary at production company Filt, said he felt there was 'something wrong with this story', he told The Times.

When the investigation was closed, he began looking through the newly released documents surrounding the case.

Of interest, he found a facial composite built from a description of the prime minister's son of a man seen loitering near the cinema where his father was shot.

There were more than two dozens witnesses to the murder, with the suspect described as being between 30 and 50, around 6ft tall and wearing a dark jacket.

Nobody was able to give a clear description of the killer's appearance in any detail.

But comparing the composite to photos of some of the main suspects from the case, Jordås' AI analysis found a match with Engström's picture of just 18 per cent.

Christer Pettersson, initially charged with the murder in 1989 but acquitted in 1990, was a 25 per cent match. Pettersson died in 2004.

But Christer And­ersson, a suspect who later shot himself dead, came out as a greater match.

Andersson, a metro driver-turned-investor who lived nearby and owned a .357 magnum like the one used to shoot Palme, was brought in for questioning in 1995.

A raid on his house turned up no leads, but later testimonies were judged untrustworthy and he failed to appear to several interrogations in the 1990s.

Andersson also refused to submit his weapon, making it the only registered .357 weapon in the Stockholm region not to be tested.

He admitted having financial trouble, and claimed to have already sold his revolver to pay off debts.

Police found some of his alibis bizarre - and it was illegal to sell a firearm to a stranger. 

He had also had his gun licence suspended for shooting at the television, allegedly as Palme appeared on screen. Andersson denied deliberately shooting the screen.

But police ultimately dropped their inquiry. 

Andersson was interrogated a total of five times between 1995 and 1998, but committed suicide in 2008 when police rang his doorbell and asked to be let in.

Jordås said that police stopped pursuing Andersson because they were convinced the Kurdish PKK movement was behind the assassination.

“If you look at the circumstances and on a practical level, a lot of things indicate it was the act of a lone wolf,” he told The Times.

Jordås believes that Andersson saw Palme enter the cinema and loitered outside with his gun.

His theories are documented in his work, The Last Book on the Murder of Olof Palme.

Myriad theories have emerged pointing in different directions over the last 20 years.

A special report shared by the CIA in 1986 dubs the assassination 'a classical KGB disinformation campaign'.

Germany's De Zeit published an article in 1995 with the suggestion that Swedish right-wing extremist police officers were behind the attack.

Others drew connections to the Yugoslavian security service, the CIA - dismissed as 'absolute nonsense' by the agency - and South Africa, as Palme opposed apartheid.

Dozens of blogs still continue to be updated today, drawing on anecdotes and evidence from around the world suggesting who really killed Olof Palme.