Lisa Black — That Darkness

Maggie Gardiner, forensic scientist with Cleveland police, sees a connection between three recent homicides. Jack Renner is a Cleveland police detective working on the same crimes. But Jack is also a killer—a vigilante. Some of the dead are his victims. This makes an interesting plot, with Maggie putting together clues and Jack trying to mislead her.

I enjoyed the book—the characters, the plot, the police work, and the different ending. It kept me reading into the wee small hours.