Genealogist Peter Sjölund from Härnösand helped the police solve the unsolved double murder in Linköping in 2004, where charges against the suspect were brought last week.
Now he and an expert group will help the police to try to solve more unsolved violent crimes - among them a number of the so-called cold cases in Västernorrland.
Only approved samples are visible
Among the current cases in the county are the double murder in Brattås in Härnösand in 2005 and the murder of 16-year-old Malin Lindström in Husum north of Örnsköldsvik in 1996.
With the help of DNA and modern genealogy, it may be possible to trace the culprits behind cold criminal cases.
But then those who have submitted DNA samples must have approved that their tests are visible - something that a third of all tested Swedes have done so far.
Hear Peter Sjölund develop it all in the clip above.