as Megan Cooper (seasons 2–3): Megan is the daughter of Virginia Cooper. As a preteen, Megan befriends a man in an online chat room. When she meets him in person, he kidnaps and rapes her. During his subsequent attempt to avoid arrest, the man is shot and killed by Virginia. Marina Durell as Sgt. Sonia Moreno (seasons 2–3): A sergeant with the NYPD, she is the mother of Nina Moreno. Zoe Dora Lukov as Melissa Lewis (season 3): Melissa is the biological daughter of Nina Moreno and her first husband Luis. Because her parents were still teenagers when she was born, she was given up for adoption. Dean Winters as Paul Delany (season 4): A firefighter with the FDNY, he is the brother of Nell Delany. Jennifer Esposito as Gina D'Amico (season 4): The former lover of Alec Stone, she is now married to his brother Frankie D'Amico. Justin Theroux as Frankie D'Amico (season 4): An organized crime boss with the Brooklyn-based D'Amico Family, he is the brother of Alec Stone. Sean Squire as Roger (season 4): Roger is the maternal half-brother of Malcolm Barker. He and Malcolm are estranged. Novella Nelson as Malcolm Barker's Mother (season 4) Law enforcement personnel Frank Pellegrino as Det. Ricciarelli (seasons 1–2) Jim Moody as Det. Otis "Old School" Washington (season 1) Gilbert Lewis as Det. Otis "Old School" Washington (pilot episode only) Takeo Matsushita as Medical Examiner Wong (season 1 episodes 3,4 & 5) Lee Wong as Medical Examiner Wong (seasons 1–3) James Saito as Det. Chang (season 1) Jon M. McDonnell as Detective Sweitek (seasons 1–2) Michelle Hurd as A.D.A. Reynolds (seasons 1–2) Edie Falco as Sgt. Kelly (seasons 2–3) James McCaffrey as Capt. Arthur O'Byrne (season 3) Joe Lisi as Chief of Detectives (season 4) Criminals John Costelloe as John Santucci (seasons 1–3): Santucci is an organized crime boss connected to the Gambino Family. He was a childhood acquaintance of Eddie Torres, and there is personal animus between the two. Ice-T as Danny "Danny-Up" Cort (seasons 1–2): A chemistry wiz, Cort was a rising drug kingpin until being apprehended by detectives from the Fourth Precinct. After J.C. Williams killed his brother in a police shootout, Cort retaliated by murdering J.C.'s pregnant fiancée Sandy Gill, igniting a bitter feud between the two men. Giancarlo Esposito as Adolfo Guzman (season 2): Guzman was a childhood rival of Eddie Torres, and as an adult