A transvestite is murdered, a surgeon is knifed outside a hospital, and Rodriguez takes the stand in Captain Fraker's trial.

Notes

• Kelly Mantle guest stars as Dan 'Monika' Hoffnagle

Sipowicz and Clark investigate when a man is severely beaten, a woman reports that her husband is missing, and testimony at Fraker's trial threaten's Rodriguez's career.

Notes

• Daniel Benzali guest stars as Sinclair and Vanessa Marcil guest stars as Detective Maria Olivera

A verdict is reached in Fraker's trial, a body is found by the river, and a middle-class housewife with a colorful past is found dead in a vacant lot.

Notes

• Daniel Benzali's last appearance as James Sinclair

Diane Russell helps the detectives of the 15th Precinct track a serial killer who targets women at an upscale bar, and Jones attempts to keep a violent father from harming his son.

• Note - Kim Delaney returns for four episodes as Diane Russell

Another young woman falls prey to a serial killer whose victims all patronize the same trendy bar; when an abusive mother is found murdered, her children are suspects. Jennifer Devlin comes clean about some issues. Connie gets some surprising news.

Notes

• Nick Offerman guest stars as Steven Debrees

When a woman survives an attack, with very similar initial circumstances to the serial killings, the detectives get some new leads; Medavoy and Jones investigate when an off-duty Narcotics detective kills his attacker in a street robbery gone bad. Russell has a breast biopsy.

Notes

• Federico Castelluccio guest stars as Brian Vaughn

The detectives get a break in the serial killer case, McDowell announces her pregnancy, and she and Sipowicz plan their wedding.

Notes

• David Marciano guest stars as 'Detective' Raymond Gerson.

A retired cop and his wife are beaten and robbed in their home, the author of a book on avoiding paying taxes has his car torched, and Michael Woodruff's foster father returns him to social services when the boy's natural father threatens his family.

Notes

• Saul Rubinek guest stars as Barry Tytell

A man who's been kidnapped and had a bomb attached to his body cuffs himself to McDowell, threatening to blow everyone up, and Devlin wants to break up with Clark.

Notes

• Jane Lynch guest stars as Susanna Howe

Sipowicz and Clark race a mobster to catch the hit-and-run driver who killed his daughter. Meanwhile a woman is raped by a man who claims he met her in an online chat room, Rodriguez resigns from the force, and Jones decides to foster-parent Michael Woodruff.

Note

• Sterling K. Brown guest stars as Kelvin George, Jerry Ferrara as Danny Puglisi, Doug Savant as Jason Foster, Louis Lombardi as Gio Puglisi, and Shannon Lucio as Courtney Bates

A cop is suspected in the murder of a man who was seeing his wife, the body of a comedy club owner is found in the trunk of a stolen car, and the precinct gets a new commanding officer.

Notes

• John F. O'Donohue joins the regular cast as Sgt. Eddie Gibson
• This is Esai Morales' last episode as Tony Rodriguez
• Anton Yelchin guest stars as Evan Grabber and Kirk Acevedo as Scott Grafton

Detectives investigate a Latino gang kingpin for murder, a man reports that his 15-year-old daughter may have been kidnapped, and Sergeant Gibson brings his obnoxious parrot to the precinct. Det. Stan Hatcher joins the 15th precinct under Andy's watchful eye.

Notes

• This is Charlotte Ross' last appearance as Connie McDowell
• Scott William Winters appears as Detective Stan Hatcher
• Michael Peña guest stars as Wilmer Lopez

The search is on for a man who kidnaps, rapes and tortures women and locks them in a dungeon, and Medavoy becomes attracted to a much older woman (Ellen Geer) who may be addicted to sex.

Notes

• Marc Vann guest stars as Paul Grady
• Ellen Geer guest stars as Veronica Lewis

An 18 year old rape-murder case of Sipowicz's is suddenly dumped in Heywood's lap the morning of the hearing to release the man on DNA evidence. Sipowicz and Clark investigate the death of a man whose brother was pursued by a bounty hunter. A woman who gave her baby away when she went to prison now wants it back.

Notes

• Jessalyn Gilsig Joins the 15th as Detective Kelly Ronson
• Dakin Matthews guest stars as Simon Clifton
• Ron Dean guest stars as Joe Brockhurst

A man has amnesia after being shot in the head. Leonard Peeler, convicted 18 years before for a rape-murder, is released based on DNA evidence. Ortiz and Ronson stumble upon a child-prostitution operation while following a lead in the amnesia case.

Notes

• Scott Klace guest stars as Linus Creel
• Katherine Narducci guest stars as Ann Marie Fusco

A former drug addict turned devoted church member is found shot in the chest. The attitude of the father of the rape-murder victim, and his refusal to provide a DNA sample, lead Sipowicz to suspect the father of the rape-murder victim. Devlin shows up at the squad, obviously off her meds.

Note

• Robin Weigert guest stars as Donna Taylor

Andy and Connie have had a little boy, Matthew Nicholas. Clark picks Devlin up after her release from the hospital. Sipowicz, Clark, Medavoy, and Jones catch the murder of a woman, whose current husband is very confrontational. An old informant of Ronson's shows up and offers her and Ortiz info about a shipment of stolen guns. Craig Woodruff is found not guilty.

Notes

• Sara Ramirez guest stars as Irma Pacheco and Mark Moses guest stars as Andrew Moss