Deadly Playmates — Bonnie Edwards

Lieutenant John Hoffman, “Tec” to his friends and co-workers, and his team of homicide detectives seek solutions to crimes of the first magnitude the evidence of which is found in the desert and mountains of Tucson, Arizona. A ferocious beating leads to the death of a pre-law student and the only witness to the attack is a young woman who remembers nothing of what occurred. But the perpetrator does not know about her lack of recall. When he finds her again, he must kill her to save himself.
A young business owner stuck with a wife whose only communications are lies, finally has had enough of her fabrications. He perceives only one solution to his problem. Tec and his crew find physical evidence of both crimes buried on Mount Lemmon.
Meanwhile one of Tec's earlier cases has come back to haunt him. Julie, the killer Tec has been trying to find over a ten-year period, has managed to escape punishment for her misdeeds until she meets the perpetrator of one of the cold cases. A chance encounter may result in a deadly dance with only one survivor.
Deadly Playmates is the fourth in the series. Deadly Payback, Deadly Pairs and Deadly Patterns are the first three books.