A thirteen-year-old boy has a videotape of a murder. Torres and Williams try to protect him; The boy's mother turns out to be Williams's old high-school girlfriend, whom he betrayed by sleeping with her best friend, Chantal.

Williams discover that Rev. Harris may be part of the bombings. Nina moves in with Eddie.

Nina and Stone go undercover as owners of a garbage company. Nina and J.C. deal with their emotions of sleeping together and G catching them.

The detectives go after a bank robbery ring. Torres and Nina get married.

When a woman becomes a fugitive, Nina uses her only resource to help find her, her daughter. Stone's life becomes threatened.

Lt. Barker recruits JC and Moreno to get the armored-car robber who killed Eddie and MacNamara.

A female bounty hunter uses Williams to help find a fugitive in protective custody. Nina and McNamara suspect a wife a recently deceased cop. Natasha visits the precinct.

Feds may be part of a drug case and McNamara might lose it all to prove it. Cooper and her husband tell their kids about their separation.

Williams and Torres pose as a substitute history teacher and a janitor at the high school where a crime was committed.

Lt. Cooper is taken hostage in her office by a man threatening to blow up the precinct if his son is not reprieved from a death-row sentence. Nina learns that the daughter she gave up for adoption 11 years ago wants to meet her.

Three youths, who were brought from Rwanda to act as mob hit men, are befriended by Father Torres. Moreno gets an inheritance; Williams disagrees with the methods of his son's hockey coach.

Willias go undercover at a prison to find evidence that will catch a drug lord. William's new friend in prison becomes involved in a murder. Torres purposes to Nina.

Torres believes the the man who confesses to a killing is taking the blame for his younger brother, who's just received a basketball scholarship to college.

Moreno poses as a firefighter in order to find out who's responsible for a female firefighter's death.

Williams investigate a case where a girl feel down and elevator shaft in her building. Torres goes shopping for Nina's engagement ring.

McNamara goes undercover involving a Chinese Mafia that has a link with his father's death. Torres asks his sister for money to buy an engagement ring for Nina.

The detectives have to prove that a Gulf War veteran has stolen missles. Williams meets with G's french teacher about G's crush on her.

With his conviction overturned, Danny Cort is back on the streets.

Williams and Torres investigate the case of a Wall Street bond salesman who claims to have shot two graffiti artists in self-defense.

Williams discover evidence relating to Martin Luther King Jr's murder.

When three youths are charged with shooting a couple, one of them insists that, while they robbed the couple, someone else fired the gun.

A war happens between east coast and west coast rappers when a california rapper is shot.

A gun-ring leader seeks revenge on Torres.

Williams and Torres investigate the murder of a free-lance writer. Moreno gets a visit by her missing husband.

The detectives suspect a mother of being involved in a carjacking involving her two children. Nina deals with her custody battle for Melissa.

Nina and McNamara go undercover to find out who tried to kill an executive. Williams and Natasha get close.

Danny Cort returns with an agenda for Williams to lose his job and his best friend--and to ""smoke [the officer's] little kid.""

The unit probes mysterious fires in the garment district.

The detectives discover that the CIA is involved in a money-laundering scheme at a bank in a Cuban neighborhood.

Lt. Barker gets involved in a bank robery. G cathes Nina and J.C. in bed together.

Toress goes undercover at an AIDS clinic to solve a murder case of a bisexual man. Cooper and Captain O'Bryne start to become closer.

The detectives go undercover on Wall Street to foil a stock-manipulation scheme.

A hit man's widow wants to become a soldier in the mob and poses as a police officer to kill a fellow crook in Williams's and Torres's precinct.

Williams poses as a freshman to investigate a racially motivated killing on a college campus.

Now physically recovered, Williams is awaiting approval to return to active duty. Torres and his new partner pose as bikers to solve the double homicide of an informant and her little girl.

Missing teens prompt a probe of a private hospital's organ-donor program.

After a young girl disappears, Torres and Williams go undercover to find her.

Torres is assigned to a case where he has to question his heritage.

A rapper is killed and his partner might be behind it all.

The death of an attorney turns out to be part of a mafia deal. Williams purposes to Sandy.

A string of robberies leads to an ex-con and his girlfriend. Torres tries to settle a dispute between his father and a mobster.

A fight promoter's death leads to a case involving blackmail, murder, and an ex-con whom Williams has helped.

Members of the unit target a modeling agent.

Agents interfere in an undercover operation aimed at a Colombian drug kingpin.

A serial killer gives male victims tainted drugs.

Torres and Williams go undercover as drag queens to solve a serial killer case.

Harlem churches are targets of bombings. Eddie tries to help Nina recover from her shot wound. Williams has issues with new comer Det. McNamara. G's friendship with a white person is being questioned.

Torres and Williams investigate a drug crime involving a former professional athlete.

A cigarette company tries to destroy a reverend. Eddie's old girlfriend is being abused.

After being freed, a policeman's murderer is killed--and the cop's partner is under investigation. Meanwhile, the murderer's girlfriend plots revenge on the gang leader who ordered the officer's death.

Torres and Nina become involved with two feuding Latino gangs.

Torres and Williams go undercover to try and find out what kind of drug crime two dead students were apart of.

Lt. Cooper's daughter ends up missing because of a pedophile she met through email.

A man gets killed by a pit bull which causes Williams and Torres to go into the world of dog betting.