Law and Order

Detective Zachary "Zack" Nichols is now-retired Detective Mike Logan's replacement in the Major Case Squad on Law & Order: Criminal Intent.


Nichols in 2009

Early life

Nichols' mother and father were both psychiatrists. Zach had entered medical school to become a doctor, but dropped out to become a police officer instead, much to the dismay of his father.

Zach once noted that he had not seen his father in "decades", even though they both live in New York City. (CI: "In Treatment")

Police force

Nichols worked with Captain Danny Ross in Anti-Crime until he took a leave of absence from the force starting in 2001 and returning in 2008, a seven-year absence. (CI: "Rock Star") While in general it was a good partnership, Ross joked that he almost got suspended once a month when they were partners. (CI: "Major Case"). He and Ross had a few cases out in Broad Channel, including a few run-ins with Jackie Dooley, an Irish crime boss who basically ran the area. The two tried to get him on a variety of crimes, including conspiracy to commit murder, but Dooley evaded the charges each and every time. (CI: "Broad Channel")

By 2009, Nichols had replaced Detective Mike Logan as Detective Megan Wheeler's new partner, whom Ross had been mentoring. His first case with her involved a stabbing victim. (CI: "Rock Star")

Ross was later found murdered and Nichols spent time consoling Danny's sister over the phone. He goes back to One Police Plaza to help Robert Goren and Alexandra Eames with the investigation. (CI: "Loyalty (1)") Nichols greatly disliked being forced to let Sayid Abdullah Hassan, the suspect in the murder of several people including his friend Ross, go free. He believed that the potential discovery of other terrorists by allowing Hassan to smuggle GPS-tagged weapons to them was not worth the lack of justice in Ross' case. He was ordered to do so by temporary Captain Eames. (CI: "Loyalty (2)")

Nichols became partnered with Serena Stevens, who both worked under the command of Capt. Zoe Callas. During his time partnered with Serena, he was brought back to Broad Channel where he was face to face with Jackie Dooley once again. (CI: "Broad Channel") He also had a case that reunited him with Lenore Abrigaille, a woman that he used to date when they were much younger. (CI: "Palimpsest")

In his final episode, he called his father Theodore Nichols for help as their suspect had multiple personalities and the department psychiatrist didn't believe in the diagnosis. (CI: "Three-In-One")



  • He is shown to be a great piano player on multiple occassions and said he thought he might have been a musician instead of a cop. (CI: "Rock Star", "Salome in Manhattan", "Passion")
  • On the USA network website, this character is listed as Zack Nichols. Multiple other sources list the character as Zach.

Icon CI.jpg Law & Order: Criminal Intent - Main Characters

Senior Detectives: Alexandra EamesMike LoganZack Nichols

Junior Detectives: Robert GorenCarolyn BarekMegan WheelerNola FalacciSerena Stevens

Commanding Officers: James DeakinsDanny RossZoe CallasJoseph Hannah

Others: A.D.A. Ron Carver • Dr. Paula Gyson