Sisters in Cold Blood: An Unwanted Sisterhood. Shaws Investigations, #1

Keri Shaw, a middle-aged Nancy Drew, discovers a confession letter dated 1909 written by a serial killer who is already dead and was never charged with a single crime. The letter holds clues to where the bodies may be buried but they need to figure out this puzzle first. Thinking that law enforcement will not bother to investigate the case, Keri begins her own investigation.  What Keri and her husband, Jade, did not account for was Detective Alison Valencia or the shadwy figure that begins stalking them. Joining forces with Detective Valencia, together, they follow the twisted path laid out by a ruthless killer years before.