As he begins his new job as squad commander, Sipowicz disobeys orders and keeps a murder investigation open... even though a Japanese man with diplomatic immunity has confessed to the crime.

After a shooting at a bar, Simone and Sipowicz are sent to the hospital and find that they know one of the victims. The whole squad is involved in the hunt for the killers.

Simone's recovery is hampered by a chest infection. The doctors differ in their opinions of which treatment to use. Sipowicz's ex-wife turns up at the station, drunk and asking for his help.

A murdered boy's father insists that a homeless man is guilty. The mother takes Russell into her confidence. Simone and Sipowicz hunt the killer.

The child of a rich family goes missing. The father suspects Israel, a local vagrant, of kidnapping him. Sipowicz has other ideas. In another case, a jewish girl is found raped and murdered on a bridge. Later, a young woman is caught using the murdered girl's credit card. Medavoy, Martinez and Russell piece together the information.

Sipowicz stays away from the squad and tries to come to terms with his loss. Evidence comes to light implicating Cullinan in more misdeeds and Sorenson turns to Sipowicz for advice. John Irvine is released from hospital, but is reluctant to return to the Precinct.

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.

When another woman is murdered by the serial killer, the detectives arrest a suspect... and discover the killer's identity; and expecting a baby, Sipowicz and McDowell decide to get married.

While investigating a random stabbing, Sipowicz becomes obsessed with his own mortality after he's nearly gunned down by a murder suspect; Medavoy takes a job as a bouncer.

Bale offers to recommend Sipowicz for the squad commander position; Ortiz and Murphy investigate the death of an Arab woman; and detectives search for the man who shot Bale.

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

A meek and mousy young woman is found beaten to death on the floor of her apartment. Her brother- in-law is very upset but not about her death--he was paying her money to use her apartment for an extramarital affair.

A squad member is shot while storming an apartment; Clark and Jones investigate the bludgeoning death of a woman whose wealthy husband was going to finance a friend's salon business.

Sorenson is missing, and a stripper is found murdered in his apartment. Medavoy and Jones investigate a killing, but the suspect identified by an eyewitness has a seemingly unshakable alibi.

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.

Sipowicz and Clark investigate when Julian Pisano is wounded in a shooting incident; McDowell and Ortiz assist a woman who doggedly pursues justice when she's conned out of $100; Clark grows concerned when his father stops returning his phone calls.

A man armed with a bomb walks into the station house and handcuffs himself to McDowell; unless the detectives release a Russian mobster from jail in one hour, the bomb will detonate.

Andy's off-duty and slightly underhanded work to prove that Hatcher killed his own wife lands him a transfer out of the 15th precinct and into the Bellevue Morgue engineered by Detective Hatcher. Meanwhile, the squad is up to their whips and chains after a dominatrix is found murdered.

The detectives continue their search for a serial killer who targets alcoholics trying to get sober; and Clark and Jones investigate a homicide linked to a woman with whom Clark had a one-night stand.

The detectives investigate the smothering death of an elderly man married to a voluptuous woman in her 20s; and a state judge pressures Medavoy and Jones to find out who poisoned her mother.

The hunt for AJ's killers continues.

As Simone's condition worsens, Lt. Fancy makes a request to the Uniformed Officers to be aware of the need for a usable heart. Simone's colleagues have to occupy their minds with the case of an old lady found hacked to pieces in her apartment. Of her two sons, one doesn't seem to care about it and the other is too full of drugs to understand what has happened. Sipowicz's mood gets him into a fight.

The detectives hunt for a man suspected of killing minorities to avenge injuries his brother suffered during the first Gulf War; Sipowicz and McDowell plan to marry.

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.

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.