The first private detective agency was established in 1833 by Eugene Francois Vidocq, a former fugitive. He used his extensive knowledge of the Parisian underworld to become a master criminologist. Vidocq was a pioneer in the use of surveillance and disguise, ballistics, card-index record keeping, and was the first to use plaster-of-paris to take impressions of shoe prints.
DID YOU KNOW? Marlon Brando hated memorizing lines so much that he posted cue cards everywhere to help him get through scenes.
He even asked for lines to be written on an actress's posterior. (That request was denied.)