Chung Ling Soo claimed that he was born half-Chinese after his Scottish father married a Cantonese woman but after his death it became clear that Chung Ling Soo's greatest illusion was the one he had woven around his own identity.
Initially it appeared that far from being half Chinese, he was in fact a 56-year-old American named William Ellsworth Robinson who had learned his trade as a humble magician's assistant in Brooklyn, New York, and that the carefully cultivated Far Eastern detail was little more than an alluring fabrication designed to boost ticket sales.
Here is Boris Karloff giving one theory people have floated for how his death happened:
Alas, the theory's probably as much fiction as the man himself; the problem was likely a poorly cleaned trick rifle, resulting in the fact that the real bullet was fired.