There's a new boss who comes from IAD with a mandate to clean up the squad. Sipowicz receives a dead rat in the mail. Clark 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.

When a convicted rapist is found shot to death, his victims become suspects in the murder investigation; and Sipowicz searches for answers when a stranger targets Theo as he walks home from school.

The detectives investigate the death of a phone-sex operator and the kidnapping of a wealthy man's son; and Clark's tryst with a murder suspect is used to derail the prosecutor's case.

After being shot outside a bar, Sipowicz discovers the identity of the person who's been harassing him.

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.

The detectives protect a scared witness testifying in a felony murder trial; Michael's father wants to regain custody; Bale finds out about Medavoy's job at the bar.

A gunman tries to kill a witness after a mistrial is declared in the Simon Kerensky arson case; and Jones goes to extremes to stop Craig from adopting Michael.

Jones becomes a murder suspect after Michael's father is shot to death; and Ortiz and Murphy investigate a molestation case that might involve a priest; Medavoy gets his hearing in trial court.

A man who cared for his brain-damaged brother is found dead; Medavoy falls for a wealthy woman while investigating an apartment rental scam; Bale tries to nail a man who offered the detectives a bribe.

While investigating a murder, Sipowicz discovers a secret about Bale; and Ortiz and Murphy investigate a shooting tied to a talented up-and-coming basketball player.

A call-girl's death is linked to other murders involving women who'd gone through rehab; Ortiz and Murphy investigate the death of an artist who'd been carrying on an affair with a wealthy man married to two other women.

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.

Sipowicz and Clark investigate the stabbing death of a coffee-shop owner who was attracted to young girls; Ortiz tries to keep her cousin out of trouble; and Medavoy and Jones link a murder to a paralyzed police officer and his family.

The detectives search for a suspect who killed a businessman by blowing up his car; and Ortiz and Murphy investigate the beating death of a student.

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.

Detective John Clark Jr., Andy Sipowicz (who just was promoted Sergeant) and a military investigator examine the murder of military recruiter Sergeant Lester Bakewell, whose affair with a female colleague caused her divorce from a retired veteran Colonel; however, the prime suspect is student Paul Corbelli, whose brother was killed in service in Iraq. A woman reports her homeless Basque uncle missing abnormally since four days; he's found dead and Detectives Baldwin Jones and Greg Medavoy investigate.

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.

Bale offers to recommend Sipowicz for the squad commander position; Ortiz and Murphy investigates the death of a Muslim woman; and detectives search for the man who shot Bale.

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.