David Margulies has played four different characters during the course of the series:
- Episode 1.13 A Death in the Family (1991) - Simpson.
- Episode 3.20 Securitate (1993) - Tommy Zanescu.
- Episode 5.15 Seed (1995) - Dr. Jordan Delbert.
- Episode 15.11 Fixed (2004) - Dr. Jack Clayburg.
Mark Lotito has played six different roles over the course of the series:
- Episode 3.20 Securitate (1993) - Bailey.
- Episode 4.4 Profile (1993) - Policeman #1.
- Episode 5.1 Second Opinion (1994) - Paramedic.
- Episode 6.18 Atonement (1996) - Nance.
- Episode 8.21 Bad Girl (1998) - Detective Mallory.
- Episode 8.22 Damaged (1998) - Detective Mallory.
- Episode 8.24 Monster (1998) - Detective Mallory.
- Episode 13.7 Open Season (2002) - Bartender.
This episode appears to be based on the large crime rate in Romania.
Chris Noth (Detective Mike Logan) & David Margulies (Tommy Zanescu) also worked together on Don't Haze Me, Bro (2012) (episode 4.4), as Peter Florrick & Richard respectively.
Chris Noth (Detective Mike Logan) & Mark Lotito (Bailey) also worked together on Innocents (2015) (episode 7.2), as Peter Florrick & Marty Pintarello respectively.