While investigating the murders of four teenage girls, the 15th squad discovers the shocking truth about the disappearance of detective Danny Sorenson.

Sipowicz is hailed a hero after killing the man responsible for Sorenson's murder. While Lieutenant Rodriguez teams up with another precinct to investigate the robbery of his mother, the squad investigates the murder of two men affiliated with NYU.

The squad investigates two homicides: the immolation of a would-be musician and the stabbing of a socialite. The newest detective to the squad, John Clark, Jr., attempts to both learn a new job and fit into the squad despite interference from his father.

The squad is joined by Eddie Gibson who's been transferred from nightwatch. McDowell and Gibson investigate the murder of a woman with MS, while the other detectives investigate the killing of a Rikers corrections officer.

When Clark's badge is stolen, the squad scrambles to find the thief before Clark must report the loss, which could ruin his career. McDowell and Gibson investigate a murder involving a young pregnant girl.

The squad investigates the theft of a baby from a hospital, and the arson of an Arab-owned business.

The squad investigates the murder of two drug dealers, and the discovery of a body mistakenly listed as a victim of the World Trade Center attack. McDowell arrests the daughter she gave up for adoption.

Sipowicz and Clark investigate the murder of a hispanic worker, while Medavoy and Jones search for a puppy-knapper who stole valuable champion bulldog pups. McDowell gets a new partner--Rita Ortiz.

Sipowicz and Clark are assigned to work with John Clark, Sr. on a murder investigation. Two good samaritans run afoul of the law when the burglar they caught dies from a head wound.

Sipowicz, Clark, Medavoy and Jones investigate a double homicide at a Latino restaurant. McDowell and Ortiz contend with a possibly mentally unstable woman who's posing as a cop.

The detectives investigate two separate murders of a college student and a Latina woman. Sipowicz goes after Mrs. Hornby's business manager. Haywood finally makes a decision about her pregnancy.

Sipowicz, Clark, Medavoy and Jones investigate the murder of an unassuming teenager. McDowell and Ortiz search for the person responsible for firing a stray bullet that killed a three-year-old girl.

The detectives investigate the separate murders of two supposedly upstanding citizens: an ex-convict turned community activist and a doctor who donated time to helping drug addicts and prostitutes.

The detectives work to solve two murders: the shooting of a rising rap star and the shooting of stripper found nailed to a table. McDowell and Sipowicz try to define their relationship.

The detectives investigate the bombing of an abortion clinic that killed a guard. The squad gets a new lead on an old murder case. Ortiz's husband, Don, is murdered by his mistress' husband.

The squad investigates the murder of a young Chinese girl along with an alleged rape case. Irvin learns his father is dying. Clark tries to find a foster home for James Kilik.

The squad investigates two homicides: a gay man who hit his head after being punched out and another man shot on the street. Rodriguez is set-up by iab to take a bribe from an old friend.

The day's cases include an armored car robbery that left one guard dead, and the homicide of a woman whose body was found in a garbage truck; Sipowicz intervenes in the iab's case against Rodriguez.

The detectives investigate two crimes: the murder of a back-alley cosmetic surgeon and a violent rape; Clark finally takes Laughlin on in the boxing ring.

Sipowicz is taken hostage in an interrogation room by a suspect in the murder of a pot dealer and two of her friends; a suburban mom found with drugs in her purse appears to be covering for her son.

An unreliable witness and an overzealous detective hinder a murder investigation; a con artist scam leads the squad to a sex-slavery operation; McDowell agrees to join Sipowicz and Theo at a theme park.

McDowell and Ortiz investigate the death of a woman found in her apartment, where an ex-con neighbor is suspect. The investigation into Scott's murder points towards his friend. Andy thinks about the future. Rita meets John's father.