Burden of Evil by Michel Monty

5.30

When the daughter of a powerful senator is kidnapped by a psychopath, the senator requests a particular homicide detective, Caitlyn Conner, to head up the case. She knows the kidnapper better than anyone else - he just killed her husband. Against the advice of her closest friend, a police psychologist, Caitlyn enters the killer's web of sadistic games and discovers the crime is far more twisted than anyone imagined.