Cold Squad is a Canadian police procedural television series that premiered on CTV on January 23, 1998, at 10 p.m., and ran for seven seasons. Led by Sergeant Ali McCormick (Julie Stewart), a team of homicide detectives from the Vancouver Police Department reopen long-unsolved, or "cold" cases (the titular "Cold Squad"), using present-day forensic technology and psychological profiling to help crack them. Cold Squad premiered simultaneously in French Canada on Séries+ as Brigade spéciale.The series was created by Matt MacLeod, Philip Keatley and Julia Keatley, and produced by Keatley MacLeod Productions and Alliance Atlantis in association with CTV Television Network, with the participation of the Canadian Television Fund (Canada Media Fund).Cold Squad is the first prime time national series produced out of Vancouver. With seven seasons and 98 episodes it became the longest-running prime time drama series on Canadian television.The cast of Cold Squad was diverse and changing. Except for Julie Stewart, almost the entire cast was replaced between the second and third seasons, and the series revamped. The revision was meant to attract a younger audience and more male viewers. (Michael Hogan, who played main character Det. Tony Logozzo in Seasons 1 and 2, appeared in the third season two-part opener episode "Deadly Games" but thereafter was gone from the series).
Starting with the third season, the "Cold Squad" division was folded into a province-wide task force and its basement setting eliminated. Along with significant variations of the title sequence (Seasons 1–2, 3–6, 7), theme music (Seasons 1–2, 3–4, 5–6, 7), new sets (Seasons 3–6, 7), and change in McCormick's hair colour from auburn to blonde along with her wardrobe (in particular her jacket), these differences contributed to a considerable reworking of the series. The only character to appear in all seven seasons was Sgt. Ali McCormick.