At roll call, the entire cast appears to have been replaced; it is revealed that this is roll call of the night shift (Lawrence Tierney plays the roll call sergeant Jenkins), while the program then follows the nocturnal activities of the day shift officers. Renko bets LaRue that he has a better driving route to the station house, planning to use his winnings to pay for a backstage pass he has purchased to meet his favorite musician, Bobby Angel; unfortunately, his idol turns out to have feet of clay (or, in this case, cocaine). Belker spends the night undercover in a dumpster waiting to arrest a cat burglar, but receives bad news about his mother's death. Joyce and Frank attend a bizarre dinner party. Jablonski spends the night at home alone (except for his dog). Lucy has some ceramics fired by a charming, but married, pottery instructor (Harper), on whom she develops a crush. Bobby and Joe try to mediate an argument about a dog stuffed into a washing machine. Henry Goldblume, while trying to mediate a dispute with militant group S.O.I.L., is taken captive at the command of their psychotic leader (Yaphet Kotto). The credits no longer feature a freeze-frame of each lead actor, but are displayed over a short clip of the actor in a scene from the show, and the footage behind the credits appears color-faded for the entire season. Dennis Franz (Norman Buntz) is added to the credits, while Barbara Bosson (Fay Furillo), Robert Hirschfeld ("Khaki Officer" Leo Schnitz), Mimi Kuzyk (Detective Patricia Mayo), and Ken Olin (Detective Harry Garibaldi) have been removed.

Lieutenant Calletano is nominated to be Captain of the Polk Avenue Precinct. Lieutenant Buntz is transferred from the Heights to take his place, and he facilitates the departure of the current Captain at Polk Avenue to ensure he keeps his position. Furillo must mediate between Mayor Cleveland and his wife when their son, Lee, is arrested on a narcotics charge; he is also placed in charge of a special corruption taskforce by Chief Daniels. Hill and Renko try to mediate tensions between a Korean storeowner and his Black clientele. Belker's car is destroyed by a car bomb on the day his girlfriend, Robin Tataglia, discovers that she's pregnant. Garibaldi, deep in debt to a loan shark, considers going bad to cover his debts; he decides not to do the bidding of his new loan shark and is fatally stabbed. Beginning with this episode, the majority of episodes begin with a pre-shift scene of one of the regulars before showing Roll Call.

A runner trying to raise money for cancer research is exploited by his coach; Garibaldi's death shakes the station house; Hill takes a direct interest in helping a black youth who robbed the Korean store get a job at the store; Furillo begins choosing personnel for the new commission on police corruption; the Lee Cleveland case comes to a tragic end and Mayor Cleveland comes to the end of his rope; Howard gets a shock from and about his latest love interest; khaki officers Leo and Natalie elope. Gregory Itzin plays Dr. Kaplan, a hospital administrator.

Lieutenant Buntz is introduced to a new partner, Detective Manny Rodriguez (Del Zamora). They arrest a criminal, handcuffed to a boiler room valve, who holds a key to Keenan's death as well as having been the man responsible for stabbing Garibaldi; the suspect is later shot while in station custody by Garibaldi's father. Belker, undercover at the bus terminal, is knocked out and loaded on a bus inside luggage. Hunter adopts a Shar Pei puppy and unwittingly joins a ponzi scheme. The Buntz/Sid the Snitch relationship begins in this episode.

Furillo's corruption commission delivers its findings and antagonizes Daniels, who implies a threat to Furillo's career; Daniels' willingness to sacrifice a night shift cop involved in an off-duty shooting that has incited public opinion has tragic results; Alan Branford returns, this time as Rambo, but comes to a tragic end after two more arrests; after exposing a corrupt division personnel officer sending incompetent female khakis who got their jobs in return for sexual favors, Buntz explores his duties as personnel officer in his own way. The new desk officer, Celeste Pattersen, makes her debut. Hunter meets dog trainer, Prunella Ashton-Wilks, for the first time.

Buntz catches a mugger only to lose him when the victim won't press charges. He later kills him during an armed robbery. Captain Furillo accuses him of intentional assassination, which he denies. Bates and Coffey have to deal with a sculptor who refuses to let anyone remove his (to some) obscene work of art. Lynnetta harangues Neal about his lack of commitment to her and her 10-year-old son, with tragic results. Belker goes undercover to learn why so many vagrants have fallen from high buildings recently and gets taken for an unexpected ride.

Sgt. Jablonski risks his own money to catch a pair of confidence men (one played by Michael Richards) in an undercover action that goes wrong; Belker acts as a courier for a pair of devious Hasidic jewelry merchants; Washington deals with the emotional aftermath of his being shot; and Captain Calletano reacts badly when Buntz accuses a lazy Polk Avenue officer of dumping vagrants in Hill Street precinct. Belker proposes to his girlfriend.

Furillo is under pressure to accept a plea bargain from a drug baron to prevent mayhem on the streets where the supply is being withheld; Goldblume has to protect a parade by blatantly anti-semitic neo-fascists, a detail that may clash with Belker's current undercover; Hill's dad visits to tell his son that he is dying, a claim Bobby isn't buying; Renko guilt-trips Hill about the way he treats his father; Belker flips out when Robin is injured in a bust of narcotics-seekers at a local clinic leading to tension in their relationship.

Belker goes undercover at the pound on a case involving animals being illegally sold for scientific testing; Buntz and Rodriguez are taken prisoner by a sadistic serial murderer (Tommy Joe Page) from Buntz's past who has escaped from a psychiatric hospital; a former major league baseball player (Tony Cotina) stopped by Washington and LaRue on a DUI is found to have a stash of drugs in his trunk, but the drugs may not be his. A journalist (Harry Steele from the magazine 'Warrior Review') is at the precinct to do a profile on Lieutenant Hunter. Robin and Belker have relationship problems. Furillo and Davenport try to buy a house. Chief Daniels is still furious with Furillo. Robin almost miscarries. Prunella Ashton-Wilks consoles Hunter after Steele decides to feature Buntz instead of him as an 'Urban Warrior'in an upcoming magazine issue.

Furillo and Bates have a day off and Goldblume is in charge. Bates bumps into her pottery instructor while shopping and sparks fly. Coffey tries to mediate between an irate landlord and a tenant who insists an image on his water-stained wall is that of the Virgin Mary; the Furillos try to renew a family relationship with his parents; Buntz uses "Officer Giblet", a turkey, to make a drug bust (the arrestee, Burton, played by Tim Russ); Former gang boss, J?sus Martinez, acts as legal counsel for Burton. The guys compete in a benefit "Olympics" competition against the local fire station personnel; Belker and Robin celebrate Christmas with a momentous decision.

Belker and Robin are planning to get married after work, but first Belker has undercover work infiltrating drug dealers; LaRue's practical joke on Renko backfires; rookie officer Ron Garfield shoots a criminal threatening him with a gun, but matters get complicated because his partner, Stegger, tries to help; a cooler containing a transplant heart is stolen from a crashed ambulance and has to be recovered within four hours; Lucy Bates reencounters Fabian DeWitt's mother.

The Internal Affairs investigation of officer Garfield continues; Belker's wedding to Robin has been rescheduled for this evening, but he is still undercover; Harper turns up at the precinct to file a complaint against Bates; Hill and Renko get a shock when delivering a corpse at the morgue - one of the corpses is Hill's father. Fabian surprises Lucy.

Fabian has turned up unannounced to stay with Bates; Hill returns home with his father's body; Hunter hits his head falling into the station basement and begins hallucinating that he's being held prisoner on a Russian freighter; Buntz is unhappy at being involved by an ex-colleague in shaking down a loan shark; Furillo is approached by a politician who thinks he should stand for mayor; Sid the Snitch is given the task of delivering Belker and Robin's wedding present, who finally get married. Grace Zabriskie plays a tattoo artist, fence and snake owner.

A smoking ban at the precinct causes tempers to fray; Bates faces a tough decision about Fabian; LaRue and Washington are still staking out the tattoo parlor for a murderer; Buntz is on the trail of a new drugs supply that's killing some of the users; Bobby Hill meets an old childhood friend.

Belker goes undercover to expose a corrupt parole officer; Goldblume clashes with Furillo over Goldblume's attempts to use his position to delay demolition of some low-rent housing in his new neighborhood; Bates makes a deal with Vivian DeWitt to sign guardianship papers for Fabian; Jablonski tries to cope with a crew making a music video in the station house, while LaRue attempts to make a quick $100 by renting out Lt. Hunter's dog to the production crew as his own; comic relief in the episode includes a hefty man who sits on people, then demands to be paid to get up. Liz Sheridan, the second Seinfeld regular this season, plays one of the older residents.

A mobster mentioned in previous seasons is extradited from Italy to stand trial locally. Before he can testify at the trial, Furillo is gunned down on the courthouse steps. The entire department mobilizes as Furillo fights for his life in the ICU. As she waits, Joyce remembers how she and Frank first met seven years before, at a trial connected to the same mobster, and how their romance developed. It is also revealed how Furillo earned the nickname 'Pizza Man'.

Buntz makes a fool of himself on a courtroom TV show where he is appearing as a witness in support of his nephew; Coffey discovers that Fabian's mother is extorting Bates for additional cash and after making clear to the mother that no more cash will be forthcoming, he insists on shepherding Bates through the process of filing official guardianship papers; LaRue and Renko try to use evidence money and a phone number found on a dead courier to complete the "buy" and bust a big case, but it gets them into deep water when the erstwhile buyers turn out to be FBI agents conducting a sting; an elderly woman (Frances Bay) threatens to blow Belker's cover at a pawnshop; tragedy hits as an off-duty Coffey is shot and killed after walking into a robbery in progress.

Bates agonizes over identifying a man suspected of killing Joe Coffey; while undercover at a supermarket, Belker is harassed by an overzealous security guard; Hunter is told to uncover a petty thief within the station - with surprising results and reasons that hit close to home; a prostitute sells out Jesus Martinez and Attorney Brown in a bribery scandal involving a judge.

Jesus Martinez is hiding out following Attorney Brown's death, trying to broker a meeting with Furillo, who is hoping to get him to incriminate Judge Hardin, but LaRue and Washington bust Martinez and endanger the deal; Belker is undercover at a building site aiming to catch a loan shark; a new officer, Kate McBride (Lindsay Crouse), is partnered with Bates; a man claiming to be Prunella's husband asks Hunter to arrange a meeting; Buntz's ex-partner asks him to smooth over a colleague, who is later found dead.

A prostitute accuses McBride of trying to blackmail her, and in the process of discussing the false charges with Bates, McBride confides that she is a lesbian;[5][6][7] two new officers, Ron Lipsky (Chris Noth) and Michael Galva, are called to deal with a suicidal man; Ballantine's mental health problems continue; Furillo is courted by a group of men to run for mayor; Buntz has to decide what to do about his ex-partner Tommy Donahue, whom he suspects of murdering a fellow officer. Laurence Fishburne appears as a pimp.

Belker meets former informant Eddie Gregg (Charles Levin) (Episodes 3.1,8-11), who is dying of AIDS; Judge Wachtel sentences a slumlord to live in one of his own buildings, but Hill and Renko have a difficult time keeping him there; Internal Affairs are investigating Buntz, unconvinced that he shot Donahue in self-defense, and his ex-captain seems out to get him; Furillo is determined to get to the truth of the Buntz case, but his actions may derail other people's plans for his future; Hunter receives a blowpipe that causes him all sorts of unexpected problems.

Hill and Renko rescue suspected multiple murderer and rapist Albert Sawyer (Paul McCrane) from a mob; a media and political circus ensues, with the arrest bringing out the worst in a lot of people; because of a mistake in judgement, Belker almost isn't there when Robin goes into labor; she delivers a healthy baby boy (whom they later name Philip, after deceased Desk Sergeant Esterhaus). Earl Boen plays a press agent exploiting the arrest.