In Shutter Island, Leonardo DiCaprio doesn't win an Oscar for portraying a law enforcement officer who investigates a disappearance only to discover that the victim is dead, and that he himself committed the crime before his sick brain blocked out that cheerful memory.
In the late 19th century, Parisian detective Robert Ledru was called in to investigate the 1887 fatal shooting of beachgoer Andre Monet. Fortunately for Ledru, he had a mountain of evidence to work with: shell casings, sock prints showing that the killer was missing a big toe, and ... some of Ledru's personal police files lying around the scene?
Even stranger was this note they found inside.
The detective realized that he also owned the same type of gun used in the murder, had no big toe, and woke up that morning with wet and sandy socks. The facts quickly started to add up to a giant arrow with "Le Culprit" written on it and pointing straight at Ledru, despite him having no memory of committing the crime. But as he thought more about it, the more sense it started to make.