At one point, Detective Joe Fontana (Dennis Farina) is asked if he'd ever worked undercover to which he replies: 'Yeah, about a million years ago, in Chicago'. He was indeed a real detective with the Chicago P.D. for many years before eventually becoming an actor.
Isiah Whitlock Jr. and Wendell Pierce appear together as defendant and his defense attorney. They had appeared together in The Wire (2002) as regulars, as a state senator and a police detective.
Isiah Whitlock Jr. played five different characters over the course of the series:
- Episode 5.11 Guardian (1995) - Antony White.
- Episode 6.12 Trophy (1996) - Simon Brooks.
- Episode 6.19 Slave (1996) - Fred Oates.
- Episode 10.10 Loco Parentis (2000) - Fred Oakes.
- Episode 11.4 Standoff (2000) - Captain Navarro.
- Episode 15.5 Gunplay (2004) - Gordon Samuels.
John Speredakos has played four different characters over the course of the series:
- Episode 2.18 Cradle to Grave (1992) - Dr. Orton.
- Episode 8.3 Navy Blues (1997) - William T. Ottenberg.
- Episode 15.5 Gunplay (2004) - Bob Ardall.
- Episode 20.23 Rubber Room (2010) - A.U.S.A. Schlicter.
This episode appears to be based on the 2003 Ronell Wilson case.