At the beginning of the season Sylvia becomes pregnant with Andy's child. A baby boy, Theo, is born towards the end of the season. This is contrasted with the fate that awaits Sipowicz's older son, Andy Jr., who announces that he is to join the police force. Andy is finally bonding with his estranged son when he is gunned down, which leads the elder Sipowicz to fall off the wagon. Andy Jr's murderers are killed themselves by Simone in an act of self defense. Bobby and Diane, whose relationship had been put on hold while she attended AA, resume their relationship only for Diane to begin drinking again when her abusive father beats her mother. Her father is eventually killed and her mother becomes the prime suspect. James Martinez and new detective Adrienne Lesniak begin an affair but only after Lesniak tells Medavoy that she is gay, then that she is not; Martinez later breaks up with her due to her controlling and unpleasant behavior, and Lesniak eventually leaves the squad. Medavoy himself leaves his wife, recognizing that she is holding him back but it is too late to save his relationship with Donna who leaves to take up a job with Apple.

ABC的警察程序剧《纽约重案组 NYPD Blue》是一部从1993年开始播出，持续了12季、多达261集的长寿剧集，它在艾美奖上斩获了多达16个主要奖项。在近期重启/续拍之风盛行的情况下，ABC以试映集制作协议预订了《纽约重案组》的续篇剧项目。 重启版由Matt Olmstead、Nick Wootton及Jesse Bochco（他是旧剧主创Steven Bochco的儿子）负责创作。剧中，旧版角色Andy Sipowitz已经去世，不过他长大后的儿子Theo（由Fabien Frankel饰演）子承父业，成为了一名纽约警探，并在第15小队着手调查父亲的谋杀案。虎父无犬子，Theo和他父亲一样，爱喝酒，但头脑冷静、思维灵活。 Alona Tal饰演女主警探Nicole Lazarus，她的个人生活有些复杂。她正在和丈夫办理离婚手续，而她这位即将成为前夫的人竟然想从Nicole的退休金……

《重案组》作为《罪案终结者》的衍生剧，将接收不少原剧卡司并展开新故事：两次获得奥斯卡提名的玛丽·麦克唐纳(Mary McDonnell)将作为新女主Capt. Sharon Raydor 领衔。剧集将探讨警察和检察官是如何确保案件成立、证据可靠并使得罪犯认罪这一过程。

两位女侦探，一位颇具慈母风范，另一位则在情感上不够成熟。她们以各自独特怪异的人生观，在侦破案件和处理个人生活时取得了不同程度的成功。

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

Each week viewers see the gritty reality of life in a New York City Police unit as the officers go about their work with a grim determination. Two partners, Detectives Andy Sipowicz and John Kelley (later replaced by Bobby Simone), are the central characters in this weekly police drama, and personify very different approaches to their difficult job. Sipowicz's brash gruffness (covering an emotional vulnerability) is tempered by the precise and controlled demeanor of the two partners with whom he has worked.

侦探们调查一家快餐店发生的多起谋杀案；一名瘾君子将自己的小女儿交给一名毒贩，以此作为逾期贷款的抵押；内部调查部门重新开启了柯肯德尔案的调查。

The detectives investigate the torture-murder of a hotel magnate's son. Russell and Kirkendall suspect that an attempted rape victim is hiding something. Simone's health begins to deteriorate.

In the fourth season of this award-winning show, the action at New York City's 15th Precinct is as hectic as ever. While Lieutenant Fancy continues as precinct commander, Detective Andy Sipowicz, although still a bit rough around the edges, has mellowed with the birth of his son. Detective Bobby Simone and Detective Diane Russell take the next step in their relationship, James Martinez becomes the Squad Delegate, and Greg Meadavoy considers becoming a surrogate father. But one thing that hasn't changed is the squad's determination to make sure the bad guys get their day in court and to also attempt to maintain a touch of normalcy in their personal lives even as they investigate cases that often put them directly in the line of fire.

Licalsi is found guilty of the manslaughter of Marino and his driver and is given a two year sentence. Because of his involvement with Licalsi, and the belief that he withheld evidence that could have given her a longer sentence, Kelly is transferred out of the 15th and chooses to leave the department altogether. He is replaced by Bobby Simone, a widower whose previous job was that of driver for the Police Commissioner. This does not sit well with Sipowicz but in time he learns to accept his new partner and, as his relationship with Sylvia leads down the aisle, asks Simone to be his best man. After an affair with a journalist who uses information that he gives her in an article, Simone begins a relationship with another new officer in the squad, Diane Russell. Sipowicz, still a recovering alcoholic, recognizes in Russell's behavior that she also has a problem and, after much prompting, she herself goes to AA. Elsewhere, due to his lack of self-belief that a woman like Donna could love him, Medavoy's relationship with her breaks down, due in no small part to Donna's visiting sister.