(written from a Production point of view)
Ralph Maurer (also known as his stage name Lev Mailer) (born 20 October 1933; age 82) is an actor and voice artist, who made two appearances in Star Trek: The Original Series. He first played Bilar in the first season episode "The Return of the Archons" and portrayed an Ekosian SS lieutenant in the second season episode "Patterns of Force".
Maurer filmed his scenes for "The Return of the Archons" on Wednesday 7 December 1966 and Thursday 8 December 1966 at the 40 Acres backlot. He filmed his scene for "Patterns of Force" on Wednesday 29 November 1967 at Paramount Pictures' "European town" back lot.
Mailer's career has spanned several occupations, including acting, directing, voice performance, and teaching acting classes. He taught for the American Film Institute and campaigned along with several other actors for greater opportunities for older actors in Hollywood. Mailer was a classmate of Desilu casting director Joseph D'Agosta, who got him his first acting jobs in The Lucy Show and Star Trek. 
Among Mailer's first television appearances are series such as The Lucy Show (1967), Mission: Impossible (1967, alongside Mark Lenard, Jack Donner, and Dick Dial), Daniel Boone (1967, with Michael Forest and Morgan Jones), and It Takes a Thief (1968, with Malachi Throne, Steve Ihnat, and Lawrence Montaigne). He also appeared in the western A Man Called Gannon (1968, with Susan Oliver and John Anderson) and the thriller Jigsaw (1968, with Michael J. Pollard and James Doohan). Also in the late '60s, he began a career as a voice artist, performing in the short film The Great Escapo (1967).
Mailer continued with appearances in the television series Hogan's Heroes (1970, with Chuck Hicks), Mannix (1970), Quincy M.E. (1977, with regulars Garry Walberg and John S. Ragin), Mrs. Columbo (1979, starring Kate Mulgrew and with Michael Durrell and Allan Miller), Dallas (1979, with Mary Crosby), and Brooklyn Bridge (1991, alongside Natalia Nogulich and Jeffrey Nordling), beside supporting roles in the television special The Star Wars Holiday Special (1978, with Mickey Morton) and in Clint Eastwood's science fiction film Firefox (1982).
Beginning in the '80s, Mailer concentrated more into his voice work and provided background voices and voice-overs for films such as the thriller The Seventh Sign (1988), the drama Avalon (1990, with Ronald Guttman), the crime drama Mobsters (1991, starring Christian Slater, F. Murray Abraham, and Seymour Cassel), the animated An American Tail: Fievel Goes West (1991, with the voice of Nehemiah Persoff), the science fiction thriller RoboCop 3 (1993), the comedy The Flintstones (1994), the science fiction blockbuster Stargate (1994, with Leon Rippy and Erick Avari), the action sequel Die Hard: With a Vengeance (1995), Roland Emmerich's blockbuster Independence Day (1996, with Brent Spiner), the television drama Lansky (1999), and the comedy Keeping the Faith (2000).
Since 2000 he has retired from the "in front of the camera" acting and taught several acting classes in Minnesota like Cynthia Uhrich.