(written from a Production point of view)
Martin "Marty" Valinsky is an actor and stuntman who worked as stand-in on Star Trek VI: The Undiscovered Country and appeared as a post-atomic courtroom soldier in the Star Trek: The Next Generation first season episode "Encounter at Farpoint". He received no credit for both appearances. His costume from his TNG appearance was sold off on the It's A Wrap! sale and auction on eBay. 
Valinsky started to work in films and television in the '80s and was featured in episodes of T.J. Hooker (1986, with William Shatner, James Darren, Marcy Lafferty, R.A. Rondell, and Vanessa Williams) and Alien Nation (1989-1990, with Eric Pierpoint, Gary Graham, Michele Scarabelli, Ron Fassler, Andreas Katsulas, Sam Anderson, Joel Swetow, Craig Richard Nelson, Henry Brown, Harvey Jason, and Mark L. Taylor). In 1994 he worked as stand-in for actor Fred Ward on the comedy sequel Naked Gun 33 1/3: The Final Insult along with fellow stand-in Dale Kasman.
Valinsky often portrayed cops and police officers and performed precision driving stunts in feature films. Among his performances are the action thriller Tango & Cash (1989, starring Teri Hatcher), the comedy sequel Police Academy 6: City Under Siege (1989, with David Graf, Matt McCoy, Kenneth Mars, Gerrit Graham, Arthur Batanides, and Dennis Ott), the crime drama Mobsters (1991, starring Christian Slater), the comedy Wayne's World 2 (1993), the comedy Black Sheep (1996), the drama Grace of My Heart (1996), the comedy Jingle All the Way (1996), the action thriller Top of the World (1998, with Peter Weller and TNG co-star Cary-Hiroyuki Tagawa), the action thriller Chill Factor (1999), John Woo's action sequel Mission: Impossible II (2000), the comic adaptation Hulk (2003, starring Eric Bana), the comedy remake The Dukes of Hazzard (2005), J.J. Abrams' action sequel Mission: Impossible III (2006), the science fiction blockbuster Transformers (2007), and the science fiction thriller The Invasion (2007).
More recent work as stunt precision driver include the superhero movie Hancock (2008), the thriller Eagle Eye (2008), the science fiction remake Race to Witch Mountain (2009, starring The Rock), the science fiction sequel Transformers: Revenge of the Fallen (2009), and the comedy Tied to a Chair (2009).