Orlagh Cassidy has played three different characters over the course of the series:
- Episode 18.19 Conversion (2017) - Cheryl Davenport
- Episode 11.11 Quickie (2010) - Mrs. Christensen
- Episode 3.2 Wrath (2001) - Valerie Plummer
Zachary Knower previously appeared in a prior episode, Closure: Part 2 (2000), as a different character.