The Vigilantes — W.E.B. Griffin

There's a sudden spike in murders -- or "targeted killings" -- in Philadelphia. But no one seems to mind much because those being assassinated are all fugitives with histories of heinous sex crimes against women and children. Making matters worse for the Philadelphia police and, particularly, for Homicide sergeant Matt Payne: the main suspect is leaving evidence everywhere -- including perfect fingerprints that cannot be traced to anyone.

Then comes the unexpected: the bodies are being turned in for cash rewards, and that's triggering copycats. Vigilante groups are cleaning up the streets with their own style of street justice. If Payne and his colleagues can't figure out who's behind this very soon, the violence could overtake them all...