(written from a Production point of view)
- You may also be looking for Mark Allen Shepherd.
Mark A. Sheppard (born 30 May 1964; age 49) is a British actor known for playing Leucon, the father of Icheb, in the Star Trek: Voyager episode "Child's Play". He is the son of fellow Voyager guest star W. Morgan Sheppard, making him of the few children of a Star Trek guest actor to appear on Star Trek. Despite a similar name, Mark A. Sheppard should not be confused with Mark Allen Shepherd who portrayed Morn on Star Trek: Deep Space Nine.
He directed his father and Star Trek: Deep Space Nine star Salome Jens in Room 101. He also appeared in Joss Whedon's series Firefly, alongside various Trek actors such as Ron Glass. He also had a recurring role as a villain in the hit series 24, which features several other Trek actors, including fellow Voyager guest star Gregory Itzin, Jude Ciccolella, Glenn Morshower, and Roger Cross.
In 2006, Sheppard appeared on Ronald D. Moore's re-imagined Battlestar Galactica which previously featured Dean Stockwell, Kate Vernon, Michelle Forbes, and Rick Worthy – although he did not perform with any of these performers. In 2007, he joined the cast of Bionic Woman, where he clashed with former Star Trek III: The Search for Spock actor, Miguel Ferrer.
In 2008 and 2009, Sheppard appeared on the series Leverage, which has also featured Saul Rubinek, Brent Spiner, Armin Shimerman, Wil Wheaton, Jeri Ryan, John Billingsley, and a cameo by Jonathan Frakes, who also directed seven episodes. He also has a recurring role as FBI agent Tanaka in Joss Whedon's fantasy series Dollhouse (2009), where he appeared in episodes with Rico E. Anderson, Erin Cummings, Clayton Rohner, Raphael Sbarge, Maury Sterling, and stuntmen Gary Wayton and Mike Gunther.
In 2011, Sheppard appeared in Doctor Who, alongside his father who played an older version of the same character. This places Mark Sheppard and W. Morgan Sheppard among the small number of actors who have appeared in both the Star Trek and Doctor Who franchises.
Sheppard is currently working as Crowley, the "King of Hell," a recurring character on the CW show Supernatural.