(written from a Production point of view)
Sean David Kenney's (born 13 March 1944; age 74) short movie and television career spans nine movies and five television guest spots – four of them on Star Trek: The Original Series. His most notable role is probably that of the mute, disfigured Fleet Captain Christopher Pike in "The Menagerie, Part I" and "The Menagerie, Part II". He also played the minor recurring character of Lieutenant DePaul. In the 1970s, Kenney appeared in the lurid exploitation film The Manson Murders, which also had Blaisdel Makee in the cast list.
Kenney filmed his scenes for "The Menagerie" on Wednesday 12 October 1966, Thursday 13 October 1966, and between Monday 16 October 1966 and Wednesday 18 October 1966 at Desilu Stage 9 and Stage 10. He filmed his scenes for "Arena" on Tuesday 8 November 1966, Monday 14 November 1966 and Tuesday 15 November 1966 at Stage 9. He filmed his scenes for "A Taste of Armageddon" on Tuesday 27 December 1966 and Wednesday 28 December 1966, also at Stage 9.
For the past fifteen years, he has been a commercial photographer in the Los Angeles area, specializing in corporate portraits and "head shots".  he will apparently be playing "Commodore DePaul", likely an ancestor, in the fan film "Star Trek: Captain Pike".