The sword of justice - Leif G. W. Persson

DS Evert Bckstrm is in charge of a rare kind of case. Finding a suspect for the murder of Thomas Eriksson - gangster lawyer and renowned defender of the guilty - isn't difficult, but narrowing down the long list of people who wanted him dead is almost impossible. Certainly the only thing the detective is mourning is his obligation to process the paperwork.
Fortunately, Bckstrm has spent his years cultivating a group of questionable acquaintances. His colleagues don't know that he only closes his cases with the help of these friends. Nor that Bckstrm owes them a few favours. But this time they're all in for a surprise because even the dirtiest cop couldn't have predicted where this trail would lead or how far from comfortable Bckstrm might be at its end.