A Swedish prosecutor closed the case of the assassination of Prime Minister Olof Palme after 34 years on Wednesday, accusing a graphic designer who died two decades ago of the country’s most notorious unsolved crime.

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 United States and Soviet Union.