Yes Rush, I remember in film Charlie was always fingering around (pun intended) with those prints. Ironically, the only time in a novel (that I recall,) when Charlie used fingerprints was the final book: "Keeper of the Keys (1932)."

Perhaps more so in the films as they were produced later as fingerprints became more standard in crime detection?

Keeper of the Keys:

"Ah, but we are more unfortunate—we live in age of science," Charlie smiled. "Great marvels happen all times, and world gets less human by minute. Sorry to say I possess utensils to get scientific here and now. I will proceed to examine fatal pistol and discover not a print on it. The suspense will be terrible. Humbly suggest you ease your mind by careful study of room."

He sat down at the desk and busied himself with his lampblack and brush.