(written from a Production point of view)
Actor Frank Emmons Overton (12 March 1918 – 24 April 1967; age 49) played Elias Sandoval in the Star Trek: The Original Series episode "This Side of Paradise". He is among the few guest star actors, in the original series, to have been listed with the credits title "Special Guest Star".
Overton had a recurring role on the television World War II series Twelve O'Clock High, which originally starred Robert Lansing. He also made guest appearances on such TV programs as Wagon Train, Perry Mason, Bonanza, and an episode of the 1960 series Tate which also featured future TOS co-star Leonard Nimoy.
He also appeared in a handful of feature films. His film debut was a bit part in 1950's Mystery Street, starring Ricardo Montalban. Later that year, he appeared in No Way Out, as did fellow TOS guest actor Ian Wolfe. He also had a role in 1957's The True Story of Jesse James. This film starred Jeffrey Hunter and also featured Frank Gorshin.
His most notable film role was as Sheriff Heck Tate in the acclaimed 1962 adaptation of To Kill a Mockingbird. This film also featured Star Trek: Deep Space Nine guest star Brock Peters and TOS guest stars Paul Fix and William Windom. Overton went on to co-star in the 1964 thriller Fail-Safe. This film proved to be his last.
Overton's life and career were cut short when he suffered a heart attack in 1967, dying at the age of 49. His death came just over one month after "This Side of Paradise" first hit the airwaves.