A tall, powerfully built man, Douglas Kennedy entered films after graduating from Amherst. Making his debut in 1940, he appeared in many westerns and detective thrillers, often as a villain. World War II interrupted his career, and he spent the war years as a Signal Corps officer and an operative in the OSS and US Army Intelligence. After the war he returned to Hollywood, where he began playing supporting roles in larger films and an occasional lead in a lower-budget film. He is most fondly remembered, though, by audiences of the 1950s for two roles: his western TV series Steve Donovan, Western Marshal (1955), and as one of the policemen taken over by the Martians in the sci-fi classic Invaders from Mars (1953).