The Vacher case took place from 1893 to 1898, and most of these books appeared right around that time. It’s amazing how much they reflect not only the science of the times, but also the era’s state of mind. I recently reread Dracula. (It kept me up nights, just as it did when I first read it at age 15.) What strikes me is how much that book reflected society’s nightmare of what the criminal was, and how closely it adhered to then-current theories about the criminal mind.