Peter Stone is a fictional character portrayed by Philip Winchester. Stone was initially a guest character as part of a backdoor pilot in the third season of the police procedural Chicago P.D. Following the success of the backdoor pilot and his character, Winchester was cast as a main character in Chicago Justice, a spin-off of Chicago P.D. During the character's time in the Chicago franchise a guest appearance was also made in Chicago Med. Following the cancellation of Chicago Justice, Winchester was cast as a series regular in Law & Order: Special Victims Unit. He departed SVU ahead of the series' twenty-first season.