Lt. Anita Van Buren
Van Buren在1993年的”Sweep”一集中，加入本劇陣容。繼承離開原先職務到反貪污專職小組的Capt. Don Cragen (Dann Florek)一角，擔任起27分區偵查隊的指揮官。本劇中她監督其他探員的工作，包括ennie Briscoe, Mike Logan, Rey Curtis, Ed Green, Joe Fontana, Nick Falco, Nina Cassady, Cyrus Lupo和Kevin Bernard。當她的探員犯錯時，Van Buren會專注在解決完成調查而非指責他們的失敗。
Det. Kevin Bernard
Detective Bernard在本劇第一次出現時是在” Burn Card”一集，擔任內務調查局的探員調查一起資深探員Ed Green介入的槍擊案，之後就開始加入本劇演員陣容。其實Bernard並不情願加入內務調查局，但被告知他待在這邊兩年後可以轉職到重案組，因此他的出現合情合理。
The show makes room for Detective Bernard in its assemble cast when he first appears in the episode "Burn Card" as an Internal Affairs Bureau (IAB) detective, investigating a shooting in which long-time Detective Ed Green is involved. The back story is that Bernard had not joined IAB willingly, but was told that he could try for a transfer to Homicide after a two-year tour of duty there, thus giving a rationale for his appearance.
Det. Cyrus Lupo
在被調任到27偵查小組前，Lupo在紐約警局的安全部門，調查包括在伊拉克，巴基斯坦和摩洛哥等海外地區的恐怖組織。而在任務中，Lupo時常單獨行動，沒有後援和武裝。在結束重大案件中，他都被稱為「這世界非常不友善的部分，沒有認證，武裝和後援」在這之前，他是27區的巡警，他的警徽號碼是2632。
Prior to his transfer to the 27th Detective Squad, Lupo spent 4 years as a member of the NYPD Intelligence Division investigating terrorist groups overseas in Iraq, Pakistan, and Morocco; while on this assignment, Lupo often worked alone, without backup and unarmed. He is cited as closing important cases in "very unfriendly parts of the world, without warrants, without a weapon, and without back-up". Before this, he was a patrolman in the 27th precinct. His shield number is 2632.
Det. Ed Green
Ed Green是被引進成為資深探員Lennie Briscoe's (Jerry Orbach)的新任跟班，承接Rey Curtis (Benjamin Bratt)的位置。Green總是希望能夠鑽法律漏洞來逮捕嫌疑犯，但這讓他的上司難以忍受，而他開始認為Briscoe年紀太大而無法勝任調查案件。Green和Briscoe曾因此有過幾次激烈的爭執。之後雖然Green逐漸開始對信任和相信他的夥伴，並且減少他鑽漏洞，遊走法律邊緣的調查方式。他和Briscoe能夠開始彼此嘲笑年齡差距，以及Green的勞力士錶和Briscoe三次失敗的婚姻紀錄。
Ed Green is introduced as senior detective Lennie Briscoe's (Jerry Orbach) new junior partner, succeeding Rey Curtis (Benjamin Bratt). Green's willingness to bend legal rules to arrest a suspect does little to endear him to his superiors, and he initially thinks Briscoe is too old to investigate crimes effectively. Green and Briscoe have several heated disagreements about the latter's capabilities. Later, however, Green grows to trust and respect his partner, as well as tone down his unorthodox investigative methods. He and Briscoe often joke about the age difference between them, as well as Green's Rolex watches and Briscoe's three failed marriages.