Law & Order: Criminal Intent, a spin-off of the crime drama Law & Order, follows the detectives who work in the "Major Case Squad" of the New York City Police Department, a unit that focuses on high-profile cases (in most cases murder, just like the regular Law & Order in this sense), such as those involving VIPs, local government officials and employees, the financial industry, and the art world; though sometimes the cases are similar to the cases from the original Law & Order show as well. From its fifth season until the beginning of the ninth season, which aired in September 2005 until April 2010, the series had generally shown four major detectives working the unit, in alternating episodes under the leadership of both Captain James Deakins and Captain Danny Ross. The unit also previously had a prosecutor assigned from the DA's office, that frequently interacted with the squad. The ninth and tenth seasons of the series showed two major detectives working the unit in all episodes under the leadership of Captain Zoe Callas and later Joseph Hannah.
One of the original characters on Law & Order, Detective Mike Logan (played by Chris Noth), appears in one episode of Season 4. At the beginning of Season 5, he is transferred from Staten Island to the Major Case Squad, where he worked until the end of Season 7.
