The Gentleman Ghost, a character created by Robert Kanigher who first appeared in Flash Comics 88 (Oct. 1947), was an elusive mysterioso foe of Hawkman throughout the late 1940s.
But the postwar world was a new one, facing fears of atom bombs and flying saucers, not things going bump in the night. Eventually, even in children’s entertainment, the supernatural was de-emphasized in favor of the super-scientific.
I suspect writer Gardner Fox, wanting to recapture some of that 1940s magic, created an arch-criminal similar to the Ghost whose powers would be pseudo-scientific rather than supernatural. He debuted in Brave and the Bold 36 (June-July 1961). In both cases, Joe Kubert did the art, and the covers are among his best.
So Carl Sands, after saving alien explorer Thar Dan of the Xarapion dimension, was rewarded with a Dimensiometer, a device that transformed him into the intangible, incorrigible Shadow Thief.
Of course, it could be that the parallels between the Gentlemen Ghost and the Shadow Thief are accidental. Superhero comics frequently play variations on a theme, and concepts get reincarnated as least as often as Hawkman and Hawkgirl.
Hawkman’s mission to capture Sands was more urgent than he realized, because only the comic book’s readers were told that overuse of the Dimensiometer would wreck human civilization by causing global climate change.
Hard for even a spook to compete with a scare like that.
