Help me find a book!?

Ok this is an adult mystery book. It's about a woman with two children and there's killings happening to mothers. One by one mothers are being killed by a sick person. In the end this reporter named Paula tricks the main character to coming out to a forest so she can kill her. The main character is saved by a guy named Fletch. The reason why Paula was killing all these woman is because the had an affair with the single guy named Fletch. Thanks so much to whoever can help me find this book!