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.

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.

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.

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.

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.

A woman is found beaten to death and left in a wooden crate. Simone and Sipowicz trace her family. Medavoy and Kirkendall hunt for the shooter of a Car Services worker. Russell is called to the hospital, where a 6-year old boy has died. His parents claim it was an accident.

A mother and 5 year-old child have been shot dead in their apartment. Simone and Sipowicz suspect that a previous break-in may be connected to the killings and that ADA Cohen might be able to help them find the killer. Russell and Kirkendall search for a missing child and trace known paedophiles in their hunt for the abductor. Sipowicz's doctor gives him some good news and good advice.

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.

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 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.

Andy and Connie return from their week's holiday with Theo. A boy goes missing, and the squad is lead to a pedophile in the area. John meets with a lawyer about his father's estate.

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.

The temperature is rising. Andy receives a death threat. A prostitute is murdered, causing IA to look at John. A huge drugs and cash hoard is found. An elderly woman is found tied up and beaten.

Clark is placed under arrest after police find heroin in his car; detectives search for clues when a woman is beaten to death with a cordless drill; a murder victim's obsession with clean living may have led to his demise.

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.

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.

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.

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.

A face from Clark's past makes an unwelcome return, while the key suspect in Andy's 18-year-old murder case turns up, face down. Jones helps Michael prepare to take the stand against his own father for killing his mom, and a man fears that his wife is going to lose her head after he loses her pricey necklace.

There's a new boss who comes from IAD with a mandate to clean up the squad. Andy receives a dead rat in the mail. John is heading off the rails. A doctor is found dead, and linked to a man who had a sex change.

The detectives tie the death of a pregnant woman to an adoption scam; Medavoy and Jones interview a woman who claims a masked assailant stole her valuable ring; and someone poisons Sipowicz's beloved fish.

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.