Detectives who are part of the NYPD's Special Victims Unit investigate crimes against the vulnerable. While the focus of other shows in the "Law & Order" franchise is primarily on murder cases, the SVU detectives frequently deal with rape and assault, in which a survivor assists with the investigation. The series cast of veteran actors includes Mariska Hargitay and rapper Ice-T, and occasional crossover episodes feature detectives from other series including editions of the "Law & Order" franchise and as well as "Chicago PD," another series from the mind of executive producer Dick Wolf.