Stieg Larsson's investigation of Swedish PM's unsolved murder revealed in new book

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.