(written from a Production point of view)
Gary B. Downey (21 December 1938 – 30 December 1979; age 41) was a stuntman and stunt actor who performed stunts in several episodes of Star Trek: The Original Series and appeared as a Tellarite inmate in the episode "Whom Gods Destroy". He worked as stunt double for William Shatner on the episode "Catspaw". He filmed his scenes for "Catspaw" on Thursday 4 May 1967 at Desilu Stage 10.
Downey also performed stunts for the television medical drama Quincy, M.E., which featured fellow Trek performers Robert Ito and Garry Walberg in its main cast. As a stunt actor, he had his largest role in the 1968 film Ice Station Zebra, which also featured Joseph Bernard, William O'Connell, Lloyd Haynes, and Jonathan Lippe.
Among his resume are films such as John Goldfarb, Please Come Home (1965, with Teri Garr and Irene Tsu), Banning (1967), Earthquake (1974, with George Murdock, Gene Dynarski, Eugene Collier, Jerry Hardin, and stunts by Tony Brubaker, Erik Cord, Paula Crist, Nick Dimitri, Gary Epper, Tommy J. Huff, and Gene LeBell), The Last of the Cowboys (1977, with stunts by Erik Cord and Hubie Kerns), and Coming Home (1978, with Bruce French, David Clennon, and Jonathan Banks).
Downey died in an automobile accident in 1979. He was 41 years old.