It was Quentin and Kit McGraw who are actually brother and sister. Quentin was the face specialiast from season 2 who helped Christian work on Sean's face when the Carver effed him up. And he was a regular on season 3 working with Christian and Sean. Kit was a detective I think.
They both used strap-ons to rape their victims because Quentin has no penis. haha, and the finale I think Quentin had Sean and Christian ready for mutilation and someone shot him(was it Kit?) And Kit and Quentin escaped to some foreign land. And S/C don't know Kit was in on it. IS that accurate?