Mark Felt 1 episode, 2016
Daniel Quinn 3 episodes, 2016-2018
Gary Fisher (1 episode, 2013)
Richard (1 episode, 2015)
Governor Samuel Reston (6 episodes, 2012-2014)
Mr. Harkin (2 episodes, 2013)
Noah Kuttler / ... (4 episodes, 2016)
Lawrence Stamberg (2 episodes, 2015)
Dr. Pelikan (6 episodes, 2010-2011)
Don Branford (2 episodes, 2010)
Aaron Stokes (1 episode, 2013)
Pastor Dunn (2 episodes, 2009)
Martin Posner (11 episodes, 2008-2009)
Livingston (1 episode, 2011)
D.A. Pratt (1 episode, 2007)
State Rep. Roy Colburn (3 episodes, 2010)
Tom Waller (1 episode, 2009)
A.A.G. Jeremy Hollis / ... (2 episodes, 2008)
Dr. Harold Abbott (89 episodes, 2002-2006)
Dr. Thomas Reed (3 episodes, 2001-2002)
Jack Schmitt (2 episodes, 1998)
General Wayne Starker (2 episodes, 1998)
Fred Mooster (2 episodes, 1996-1997)
Julian Wheeler (3 episodes, 2001)
Cmdr. John Flagler (3 episodes, 1999-2002)
David Gardner (1 episode, 1998)
Eliot Ness / ... (44 episodes, 1993-1994)
Martin (2 episodes, 1995)
Noah Kuttler / The Calculator
Bruce Bronstein 1 episode, 2019