Dominic Caruso is the son of Jack Ryan's sister and her husband Mr. Caruso, twin brother of Brian Caurso, grandson of Emmett Ryan, nephew of Jack Ryan and Caroline "Cathy" Ryan and cousin of Sally Ryan, Jack Ryan, Jr., Kathleen Ryan and Kyle Ryan. Dominic was a Special Agent working for the FBI, until the rape and murder of the little girl and the shooting death of the killer, that he decided to join his brother Brian and his cousin, Jack Jr in the new Agency in The Teeth of the Tiger. His brother Brian was killed in Dead or Alive.