The Killer's Wife by Bill Floyd

After helping convict her serial killer husband, a single mother must revisit her dark past to save her son's life in this debut psychological thriller.

Six years ago, Leigh Wren testimony against her own husband helped put him on death row for a series of gruesome murders. Now, with new names and a new life, she and her son are starting over in North Carolina. But everything starts coming apart when someone exposes her. And just as her traumatic past comes to light, a new killer emerges—one whose methods are frighteningly similar to her ex-husband's. 

It soon becomes clear that the copycat killer is targeting people tied to Leigh's former life. Now, to protect herself and her son, Leigh must probe the darkest corridors of her past. She must also confront her own lingering sense of guilt. Leigh always professed her ignorance, but how complicit was she in her husband's horrific murder spree, as it was taking place?