(written from a Production point of view)
Keiffer, a former K.I.C.K. Super Middleweight Kickboxing Champion, started his film career as a background performer and fighter in movies such as the action films Shootfighter: Fight to the Death (1992, with Chris Torres), Bloodfist IV: Die Trying (1992, with Gene LeBell), Maximum Force (1992), Dragon Power (1993), Full Contact (1993), Firepower (1993), Bloodfist V: Human Target (1994), Guardian Angel (1994, with Marshall R. Teague), and Fists of Iron (1995, with Matthias Hues).
The following years Keiffer performed stunts and portrayed action parts in the action thriller Fist of the North Star (1995, with Malcolm McDowell, Clint Howard, Tracey Walter, and stunts by Johnny Martin and Scott McElroy), the fantasy action Mortal Kombat (1995, with Cary-Hiroyuki Tagawa, Lloyd Kino, Frank Welker, and stunts by Dana Hee, Jeff Imada, and Chris Torres) and its sequel Mortal Kombat: Annihilation (1997, with Reiner Schöne, Brian Thompson, Musetta Vander, Marjean Holden, Lance LeGault, Carolyn Seymour, and Dana Hee), Joel Schumacher's superhero movie Batman & Robin (1997, as Ice Thug along with Steve Blalock, Mark Chadwick, Jean-Luc Martin, Jim Palmer, Chris Sayour, and Paul Sklar), and Barry Sonnenfeld's science fiction comedy Wild Wild West (1999, with Musetta Vander).
He appeared in episodes of the television series The Pretender (1998, with Leigh Taylor-Young), Charmed (1999 and 2004, with Ian Abercrombie and stunt coordinator Noon Orsatti), The X-Files (2000, with Mark Chaet), Nash Bridges (2000), V.I.P. (2001, with stunts by Jeff Cadiente, Henry Kingi, Jr., and Darlene Ava Williams), J.J. Abrams' Alias (2001, with Daniel Betances, Derek Mears, Greg Grunberg, and stunts by Shauna Duggins), Power Rangers Wild Force (2002), CSI: New York (2005, with Eugene Collier and Derek Mears), CSI: Miami (2005, with Brett Cullen), Deadwood (2005-2006, with stunts by Christopher Doyle, Thomas DuPont, and Bobby Aldridge), and The Shield (2007).
Further film credits include Bryan Singer's superhero film X-Men (2000, starring Patrick Stewart, Famke Janssen, Bruce Davison, and with Scott Leva), Tim Burton's science fiction remake Planet of the Apes (2001), Steven Spielberg's science fiction thriller Minority Report (2002), Peter Berg's action thriller The Rundown (2003, sarring Dwayne Johnson and with William Lucking, Jeff Chase, and Todd Stashwick), the science fiction film Sky Captain and the World of Tomorrow (2005, with stunts by Randy Hall, Brian Simpson, and Monica Staggs), Joss Whedon's science fiction film Serenity (2005), the thriller Southland Tales (2007), the comedy Epic Movie (2007), and the action sequel Live Free or Die Hard (2007, with Tim Russ).
More recent projects include episodes of Breaking Bad (2008), House M.D. (2008, starring Jennifer Morrison), and Eleventh Hour (2008, with Tanner Gill), the action film Redbelt (2008, with Scott Barry, Mike Genovese, and Gene LeBell), Steven Spielberg's action sequel Indiana Jones and the Kingdom of the Crystal Skull (2008), and the action film Bitch Slap (2009, with Erin Cummings, Robert Mammana, Danny Nero, Eurlyne Epper, Karen Austin, and stunts by Thom Williams).
In 2009 Keiffer was part of the stunt crew which received a Screen Actors Guild Award nomination for Outstanding Performance by a Stunt Ensemble in a Motion Picture for Indiana Jones and the Kingdom of the Crystal Skull. Fellow Trek stunt performers shared this nomination: Jon Braver, Keith Campbell, Lauro Chartrand, Ken Clark, Phil Culotta, Anthony De Longis, Kevin Derr, John Dixon, Danny Downey, Shauna Duggins, Thomas DuPont, Peter Epstein, Ian Eyre, Jeremy Fry, Charles Grisham, Jim Hart, Mike Justus, Rob Mars, Mike Massa, Derek Mears, Victor Paguia, Jim Palmer, Monte Rex Perlin, Darrin Prescott, Brian Simpson, Gary Ray Stearns, Douglas Tait, Trampas Thompson, Tim Trella, Gary J. Wayton, and Webster Whinery, Jr..