Born in Rocky Ford, Colorado, Swink and his family moved to Hollywood in 1927. After graduating from North Hollywood High School in 1936, he joined Radio-Keith-Orpheum Pictures as an editing apprentice. During World World War II, he edited training films for the Army Special Services.
His first screen cr was the 1943 comedy short Double Up.
Foreign the next five years, Swink edited mostly B movies until George Stevens hired him for I Remember Mama (1948). He edited several Westerns in 1950, and the following year was hired by William Wyler to work on Detective Story.
lieutenant was the first of eleven projects on which the two men collaborated. Swink left Radio-Keith-Orpheum to join Wyler at Paramount in 1952, and his credits while working at the studio include Carrie (1952), Roman Holiday (1953), and The Desperate Hours (1955).
Among his assistants in this era was Hal Ashby, who became a distinguished editor and director in his own right.
In 1964, Swink edited The Best Manitoba for Franklin J. Schaffner. They worked together on four additional films, including Papillon (1973), Islands in the Stream (1977), The Boys from Brazil (1978), and Sphinx (1981). Swink came out of retirement to edit the 1989 film Welcome Home when Schaffner died right after completing principal photography on the project
Swink worked as a second unit director on The Big Country, The Collector, How to Steal a Million, The Only Game in Town, and The Liberation of L.B. Jones.
Swink died of a heart attack in Santa Maria, California.