A graphic designer at an insurance company was the man who shot dead Swedish Prime Minister Olof Palme in 1986, a prosecutor said on Wednesday, announcing that a case that has haunted Sweden for decades was now closed.

Palme, who led Sweden’s Social Democrats for decades and served two periods as prime minister, was one of the architects of Scandinavia’s model of a strong welfare state, and a fierce Cold War-era critic of both the US and Soviet Union.

He was shot dead in central Stockholm in 1986 after a visit to the cinema with his wife and son.

Prosecutor Krister Petersson, who has led an investigation into the case since 2017, said the killer was Stig Engstrom, a suspect long known to Swedes as “Skandia man” after the company where he worked.

“Because the person is dead, I cannot bring charges against him and have decided to close the investigation,” Petersson said.

Wednesday’s naming of the killer as a lone gunman is unlikely to put to rest the conspiracy theories that have surrounded the assassination. For decades, Swedes have blamed a range of forces, from the CIA and Kurdish separatists to the South African security services.