The original cast members in the first season of Law & Order: SVU, in 1999, included Dann Florek, Mariska Hargitay, Christopher Meloni, and Richard Belzer. Other recurring roles included Dean Winters, Michelle Hurd, Isabel Gillies and Angie Harmon.
As with other Law and Order franchises, the cast went through regular changes in much the same way that a normal police unit might. Florek himself was a transplant from the original Law and Order series, where he played then Detective Cragen from 1990 to 1993. Dean Winters would later depart the series while it was still in its first season. Later, Michelle Hurd would depart in 2001, and she was replaced by Ice-T. Ice-T would remain a series regular.
Most recently, Christopher Meloni departed the show in 2011. The ever changing line-up is a close approximation to the conditions within a high stress police unit, making the departures and arrivals of various cast members seem less out of place than they might in any other setting. Other cast changes have frequently revolved around the role of the assistant district attorney assigned to the unit, such as Stephanie March, Diane Neal, Sharon Stone, Raul Esparza and Melissa Sagemiller, among others. In February of 2015, NBC announced that Law and Order: SVU would return for its 17th season.