Prior to his work on Star Trek, Tompkins appeared in episodes of The Facts of Life (1984), L.A. Law (1987, with Corbin Bernsen, Gary Armagnac, and Stanley Kamel), Murder, She Wrote (1987, with George Takei, Mark Phelan, and Adrienne Barbeau), Matlock (1987, with Dakin Matthews and Jason Wingreen), Dallas, Days of Our Lives, Starman (1987, with Michael Cavanaugh, Brooke Bundy, and Philip Weyland), and Hunter (1989, with Angela Paton), and in the television thriller By Dawn's Early Light (1990, with Kieran Mulroney, Nicholas Coster, Ken Jenkins, Randal Patrick, Daniel Benzali, Robert O'Reilly, Ann Gillespie, Glenn Morshower, Jon Steuer, Steve Rankin, Mike Gomez, and Scott Trost).