(written from a Production point of view)
David Kagen (born 7 September 1948; age 70) is an actor who played the Tandaran Major Klev in the Star Trek: Enterprise first season episode "Detained". He filmed his scenes for this episode between Wednesday 6 February 2002 and Friday 8 February 2002, on Tuesday 12 February 2002, and on Wednesday 13 February 2002 on Paramount Stage 8, 9, and 18. His costume from this episode was later sold off on the It's A Wrap! sale and auction on eBay. 
Kagen was born in Somers Point, New Jersey and has worked as an acting teacher beside his on-screen career. He has taught actors such as Ted Danson, Alec Baldwin, Michelle Forbes, and Ally Walker and has coached alongside fellow Star Trek actors Andrew Borba, Frank Collison, Jordan Lund, Brad Greenquist, and Brett Rickaby for over thirty years in David Kagen's School of Acting.
Kagen has appeared in several television series, including guest appearances in Hill Street Blues (1985, episode "G.Q.", with James B. Sikking, Barbara Bosson, and Jimmie F. Skaggs), The A-Team (1986, episode "The A-Team is coming, The A-Team is coming", with series regular Dwight Schultz), Beverly Hills, 90210 (1994, episode "Cuffs and Links", with Dina Meyer, Lawrence Monoson, and Peggy Roeder), Profiler (1997, episode "Primal Scream", with regular Dennis Christopher), Angel (2000, episode "Are You Now or Have You Ever Been", with Tony Amendola and Tommy Hinkley), Without a Trace (2003, episode Fallout: Part 2, with series regular Enrique Murciano and with guest star Barbara Tarbuck), and CSI: Crime Scene Investigation (2005, episode "Room Service", with Wallace Langham, Art Chudabala, and Tess Lina).
Kagen has also appeared in films such as the horror sequel Jason Lives: Friday the 13th Part VI (1986, with Renée Jones), the thriller Body Chemistry (1990, starring Mary Crosby), the science fiction film Hologram Man (1995, starring Michael Nouri), and the drama Shackles (2005, with Dan Desmond, Sandra Nelson, and Deborah Strang).