L'empreinte ou La main rouge

Who killed this man to rob him of his money in this notorious neighborhood of Paris? The usual local scoundrel such as the one that has almost been lynched by the mob and arrested by the police? Not at all. In fact the poor man is innocent, even though appearances are deceiving. The real culprit is a respectably-looking man who, to divert suspicion, has put some blood of his victim on his fingers and some of the stolen money in his pockets while he was asleep.