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His mustache was into reaching heaven.

If you are a murderer with a time machine, the era right before Lacassagne joined the Forensic Medicine Department of Lyon University is the place to be. Only two things could get you into jail: a forced confession or witnesses who saw you do the deed. Plus, the prevailing theory of the day was that you could spot a criminal by the shape of his forehead and the length of his arms. So if you didn't go around looking like an ape-man, you could probably get away with murder. Lacassagne disagreed. While treating soldiers during military service in Algeria, for example, the doctor decided that tattoos gave insights into the criminal mind -- so he collected and categorized 2,000 images. Can you imagine what he could have done with Instagram? This guy was so into criminals that he actually invented the field of forensic psychiatry, which is basically just the simple idea of asking "Why? Why would someone slit this person's throat and then pee on him?" No one thought to ask the hard question of "why" before Lacassagne.

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More importantly, Lacassagne wasn't afraid to look at dead bodies, no matter how horrifyingly disgusting they were. By studying the movement of insects on a dead body, for example, he could figure out how long the deceased had been decaying. He was the first to realize that blood splatter at the scene of the crime could tell you about the victim's injuries. He was the first to figure out that you could totally put a gun or knife in a dead man's hand before the rigor mortis set in, so the old "make it look like suicide" trick wouldn't work on him. He asked criminals to write about themselves from prison so he could study their minds. Then when they died, he LITERALLY studied their minds.

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So when authorities finally caught their "French Ripper," Lacassange was asked to analyze him. Was he too insane to go to the guillotine? Nope, said Lacassagne of the terrible, horrible, no good, very bad man. This guy was what we would now call a psychopath, someone who was totally aware of his actions but lacked empathy or remorse. Only they didn't have a word for psychopaths then, because it didn't exist, so he invented it. Standard scientific procedures for autopsies -- all Lacassagne.