Chicago P.D. Season 4 Episode 11 : You Wish

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 runs Jimmy's DNA to confirm that he is actually Lindsay's father.