In February 1986, the prime minister of Sweden was walking home from the cinema, when a man stepped out of a shop doorway and shot him in the neck with a .357 Magnum. The killer ran down a side street – and disappeared without a trace.

The mystery surrounding Olof Palme’s death is a Swedish national obsession that's barely left the headlines in the decades since. Hundreds of theories, from international hitmen to lone gunmen and police conspiracies, have swirled around one of the most extensive murder investigations in history.

And then, in 2020, investigators called a press conference – to announce that they had finally found the killer…