S20, E17: When Detectives Cyrus Lupo (Jeremy Sisto) and Kevin Bernard (Anthony Anderson) arrive on the scene of four fallen police officers, they have to act fast to find the shooter. With a room full of witnesses, they have a description of the culprit but little else. The case becomes even more complex when the detectives discover that the police officers may have known the shooter. The investigation quickly leads them to a circuit of drug dealers, a jealous husband and a remorseful judge who are all pieces of a larger puzzle. Also starring: S. Epatha Merkerson (Lieutenant Anita Van Buren), Sam Waterston (District Attorney Jack McCoy), Alana De La Garza (Connie Rubirosa) and Linus Roache (Michael Cutter).