Matthew Gray Gubler (Dr. Spencer Reid) and Shemar Moore (Derek Morgan) are the only two actors to appear in all "Criminal Minds" episodes to date. Thomas Gibson (Aaron Hotchner) is credited in all episodes, but he did not actually appear in one of them.
Other actors to have past or current recurring roles on the show include Kirsten Vangsness (Penelope Garcia), A.J. Cook (Agent Jennifer Jareau), Joe Mantegna (David Rossi), Paget Brewster (Emily Prentiss), Mandy Patinkin (Jason Gideon), Jennifer Love Hewitt (Kate Callahan), Lola Glaudini (Elle Greenaway), Jeanne Tripplehorn (Alex Blake) and Jayne Atkinson (Erin Strauss).
Many of the actors on the show had established film or TV careers before being cast in "Criminal Minds." Patinkin was well-known for his role in "The Princess Bride." Mantegna had been in several films, including "Baby's Day Out" and "The Godfather Part 3." Moore was part of the cast of "The Young and the Restless." A.J. Cook acted in "The Virgin Suicides." Gubler, a recent film school graduate at the beginning of the series, and Vangsness, a theater actress, were relatively unknown in the film world before being cast.
Some of the actors, including Gubler, Mantegna and Gibson, have also directed episodes of the show, while Vangsness has co-written the script for an episode.