|Who did it?|
Turns out author Larsson had gathered extensive information (15 boxes!) about the murder of Swedish P.M. Olof Palme. Reports say Larsson spent nearly a year gathering information. Larsson did come up with a suspect and passed the name on to police. According to the post police did interview Larsson's suspect but did not (and do not) consider him a person of interest. The murder was committed in 1986 and still remains a mystery today.
If you're interested in reading about Larsson's investigation, tootle over to Stieg Larsson