You Wish

S4, E11: When a mutilated sex offender is found dead, it is unclear if he was the victim of a hate crime, sexual assault or self mutilation. As Intelligence questions those related to the case, they find themselves up against a private "special police" force who may be covering up illegal activities. Meanwhile, Halstead (Jesse Lee Soffer) runs Jimmy's (guest star Tony Crane) DNA to confirm that he is actually Lindsay's (Sophia Bush) father.