The screenplay was based on the short story "Stock Shot" by Robert Leslie Bellem that appeared in the June 1944 issue of "Hollywood Detective" magazine.
For those who prefer accuracy in the data, Empire Universal Films [ca] was NEVER a distributor of of films made by Republic PIctures Corporation. The name of the Republic distributor in Canada was Empire Films Ltd. For reasons unknown this inaccurate keeps being added to Repubic Pictures Corporation films.