(written from a Production point of view)
Actor Terry O'Quinn (born 15 July 1952; age 63) appeared as Admiral Erik Pressman in the Star Trek: The Next Generation seventh season episode "The Pegasus" in 1993. Despite playing Riker's much older superior officer, in reality O'Quinn is only one month older than actor Jonathan Frakes.
One of O'Quinn's most memorable roles was Jerry Blake (aka "The Stepfather") in the 1987 horror film The Stepfather, a role he reprised in the 1989 sequel The Stepfather II, co-starring Meg Foster. Other notable roles include aviator Howard Hughes in the 1991 film The Rocketeer (co-starring fellow Trek actors William O. Campbell, Paul Sorvino, Ed Lauter, Tiny Ron, Max Grodénchik, Clint Howard, and William Boyett), as well as regular roles on the Chris Carter-produced series Millennium and Harsh Realm. He also played the role of Captain (and later Admiral) Thomas Boone in ten episodes of CBS's court-room drama JAG (upon the promotion, Mark Metcalf would play Boone's replacement). O'Quinn played three separate characters in The X-Files, the first as Lt. Brian Tillman in the second season episode "Aubrey," the second as SAC Darius Michaud in the X-Files movie Fight the Future, directed by Rob Bowman, and the third as "Shadow Man" in the ninth season episode "Trust No 1," credited as "Terrance Quinn." The X-Files was executive-produced by John Shiban.
O'Quinn made his feature film debut in the 1980 drama Heaven's Gate, starring Brad Dourif. In 1988, he played Alex McSween in the action western Young Guns, a film which also featured Brian Keith. In 1990, he co-starred with George Takei in the war drama Prisoners of the Sun. The following year, he co-starred with DS9 guest star Tim Ransom and ENT guest star Dean Stockwell in the telefilm Son of the Morning Star.
He played the role of Mayor John P. Clum in 1993's Tombstone, which tells of the battle at the OK Corral. In 1996, he co-starred with Whoopi Goldberg, Susanna Thompson, Virginia Madsen, Richard Riehle, Bill Cobbs, Thomas Kopache, Bill Smitrovich, and the late Brock Peters in Ghosts of Mississippi. In 2000, he had a role in HBO's Rated X, alongside DS9's Nicole de Boer.
O'Quinn had a recurring role as FBI Asstant Director Kendall on the J.J. Abrams-produced ABC drama Alias. He then began playing the mysterious John Locke on another of Abrams' television series, Lost, alongside fellow Trek alumni Daniel Dae Kim, Titus Welliver, Fionnula Flanagan, Alan Dale and Sam Anderson. In the Lost episode "All the Best Cowboys Have Daddy Issues", one of the other characters asks O'Quinn's character if he has seen Star Trek, while talking about the redshirt curse of the Original Series. O'Quinn's character replies, "No, not really." When the phenomenon is explained to him, he remarks that Kirk sounds like a "piss poor captain."
O'Quinn earned his first Emmy Award nomination for his role on Lost in 2005. In 2007 he received another nomination, which he won, beating out, among others, William Shatner, who was up for Boston Legal. Lost ended its run in May 2010. Since then, O'Quinn worked on the television movies Hallelujah (2011, with Brett Cullen and Josh Clark) and Taken from Me: The Tiffany Rubin Story (2011) and on the television mini series Ring of Fire (2012).
Besides a recurring role as Joe White on CBS television remake of Hawaii Five-0 (2011-2012, alongside Daniel Dae Kim), O'Quinn more recently had guest parts in episodes of Falling Skies (2012, with Matt Frewer) and 666 Park Avenue (2012, with Vanessa Williams).