Sikking's feature career goes back to the mid-1960s. He can be glimpsed in "Von Ryan's Express" (1965) playing a soldier alongside Frank Sinatra. A notable early credit had him playing a hit man in John Boorman's classic gangster film "Point Blank" (1967). Sikking was also a supercilious starship captain cut down to size in "Star Trek III: The Search for Spock" (1984). His other film work includes "Charro!" (1969), "The Magnificent Seven Ride" (1972), "The Electric Cowboy" (1979). "Ordinary People" (1980), "Outland" (1981), "Narrow Margin" (1990), and "The Pelican Brief" (1993). In the latter blockbuster, he played the FBI director.