In the late 19th and early 20th century, being a criminal was a lot easier than it was now. Before the advent of drivers license and social security cards, it was pretty easy to change your identity. Maybe you'd move to a different town or a different part of town, but basically, if the police were after you, you just picked a new name. Fingerprinting didn't really start until 1903 and even then was pretty localized and not overly scientific.
But in the late 1800s Inspector Thomas Byrnes came up with the Rogues Gallery, a series of what we would now call mug shots, to help identify criminals and their many, many aliases. This was a game changer, because when the police brought someone in, they couldn't just give an alias. Now there was a wall of faces to show if the person had committed a crime before.
That was only if they could catch you...
Bonus Point Time: post a picture of yourself on ANY social media site for the Devil's Own Rogues Gallery. You can post a mug-shot style picture OR a picture of you evading capture. Blur your face, hide your features beneath the brim of a hat, turn your head just before the camera snaps. Or stare at the camera head on...daring it to arrest you.
Whatever you choose... be sure to pick an ALIAS. No good gang member wants the police to be able to trace them back to the gang, after all.
Be sure to tag me in the picture and use the #THELASTMAGICIAN on the post.