Stieg Larsson, author of “The Girl with the Dragon Tattoo,” became one of the world’s most famous crime novelists with a trilogy that has sold more than 80 million copies. But before that success, Larsson spent years researching the assassination of Sweden’s prime minister, the left-wing social Democrat Olof Palme, who was gunned down on the streets of Stockholm in 1986. More than 30 years later, a journalist has used Larsson’s archives to crack open the cold case. Don Dahler reports. Source