Wolves and angels

"The lifeless body of an unidentified disabled man is found on a cold fall night in the Finnish city of Tampere. The police learn that the deceased was a member of the "Fallen Angels," a gang of wheelchair-bound motorcycle enthusiasts. Soon there are more attacks on the disabled and ailing. Detective Sakari Koskinen and his eccentric team spring into action: How are these events linked? Is there a serial killer on the loose playing angel of mercy?"--P. [4] of cover.