[7] The following year Killy assisted Philip Moeller on the classic drama The Age of Innocence, the first talking version of the novel, starring Irene Dunne and John Boles.

[13] The pair co-directed two more films before Killy was given his first solo directing assignment, 1936's Second Wife, starring Gertrude Michael and Walter Abel.

[15] Some of the oater collaborations between Killy and Holt include: The Fargo Kid (1940), Wagon Train (1940), Along the Rio Grande (1941), and Land of the Open Range (1942).

[16][17][18][19] In the mid-1940s, a young actor, Robert Mitchum, was signed to a seven-year contract with RKO, with the intent of making B-Westerns based on Zane Grey novels.

[22] Even after getting the opportunity to take the helm of films, Killy was one of the rare people to continue to work at the assistant director level.

[31] In the late 1940s through the 1950s, Killy would also occasionally work as a production manager on such films as: Blood on the Moon (1948), The Big Steal (1949), Angel Face, Jet Pilot, and All Mine to Give (1958).