(written from a Production point of view)
John Saint John (also known as John St. John) is an actor and stunt performer who appeared in at least three episodes of Star Trek: The Next Generation and Star Trek: Deep Space Nine. Beside his two Human appearances, he also portrayed a background Klingon in the latter series.  The robe from this appearance was sold off on the It's A Wrap! sale and auction on eBay. 
Saint John graduated from the John Marshall High School in Los Angeles, California in 1976 and attended the Los Angeles Trade Tech College. He is a Screen Actors Guild member since 1994 and has worked as security officer, camera operator, and technical adviser. He was a regular background actor in the television series Dr. Quinn, Medicine Woman between 1993 and 1998, in which he appeared alongside regulars Joe Lando, Chad Allen, Frank Collison, Barbara Babcock, Erika Flores, Helene Udy, Gail Strickland, and Nick Ramus. Saint John worked as a stand-in on the television series Family Law (starring Christopher McDonald, Julie Warner, and Salli Elise Richardson), performed stunts and precision driving stunts in the action film A Man Apart (2003), the remake Starsky & Hutch (2004), Wes Craven's horror film Cursed (2005), and more recently in the superhero movie Iron Man (2008).
In addition he portrayed background and supporting roles in the television series Roswell (starring William Sadler and produced by Jonathan Frakes), Parent Hood, Grey's Anatomy, My Name is Earl, and The Shield, the thriller On Deadly Ground (1994), the drama Sioux City (1994, with Salli Elise Richardson), the science fiction thriller The One (2001), the comedy Say It Isn't So (2001), the short comedy Pennyman (2002), Spike Jonze's drama Adaptation. (2002), and the drama Destricted (2006).