A man, found stabbed in an alley, turns out to be Nicholas, the vagrant who was being protected at the station. The search goes on for Diego, who was named, by Nicholas, for a previous killing. Sorenson gets into an argument with Sgt. Mahoney, for releasing Nicholas. The family reveal that Nicholas wasn't all he appeared to be, giving Sorenson and Sipowicz further ideas on the killer's identity.
Russell, Medavoy and Jones investigate a double shooting in an apartment, which looks like a murder/suicide until ex-detective Harry Denby's name is linked to one of the deceased.