Beyond the Wall of Sleep by H.P. Lovecraft

"Beyond the Wall of Sleep" is a science fiction short story by American writer H. P. Lovecraft, written in 1919 and first published in the amateur publication Pine Cones in October 1919.
An intern in a mental hospital relates his experience with Joe Slater, an inmate who died at the facility a few weeks after being confined as a criminally insane murderer. He describes Slater as a "typical denizen of the Catskill Mountain region, who corresponds exactly with the 'white trash' of the South", for whom "laws and morals are nonexistent" and whose "general mental status is probably below that of any other native American people".