A man named Billy Milligan known to have 24 alternate personalities, becomes infamous as the first man to plead insanity and avoid charges for his crimes after several years in a mental institution. But what exactly does insanity entail? Should pleading insanity be claimed as legal? Find out on this episode of the Case Files with Jacob Dougherty and Georgia Scherrer.

Correction: Ted Bundy died in an electric chair.