Though born in Spokane, Washington, Martin's family moved to a Mexican neighbourhood in West Hollywood, California, where he learned to imitate his friends.
Hollywood's World War II films often featured many ethnic American enlisted men, and Martin first played Chito Rafferty as a contemporary air crewman in Bombardier.
[5] Martin returned to RKO in the same year in his first appearance alongside Holt in Under the Tonto Rim, the first of 29 films they did together that were initially based on stories by Zane Grey.
As B westerns and exclusive studio contracts gradually ended in the 1950s, Martin found himself out of work and unable to find any due to his ethnic characterisation.
The character went on to appear in a further 34 films, all of them westerns: 1944's Nevada and 1945's West of the Pecos, both of which starred Robert Mitchum; 1945's Wanderer of the Wasteland, which starred James Warren; 1946's Sunset Pass and 1947's Code of the West, in which the role was not played by Martin but by John Laurenz; then a further 29 films, all of which featured Chito Rafferty as the sidekick to a different hero, always played by Tim Holt: Thunder Mountain, Under the Tonto Rim and Wild Horse Mesa in 1947, Western Heritage, The Arizona Ranger, Guns of Hate, Indian Agent and Gun Smugglers in 1948, Brothers in the Saddle, Riders of the Range, Rustlers, Stagecoach Kid, The Mysterious Desperado and Masked Raiders in 1949, Storm Over Wyoming, Rider from Tucson, Dynamite Pass, Border Treasure, Rio Grande Patrol and Law of the Badlands in 1950, Saddle Legion, Gunplay, Pistol Harvest, Hot Lead and Overland Telegraph in 1951, and Trail Guide, Road Agent, Target and Desert Passage in 1952.