Sometime between 1:30 a.m. and 2:00 a.m. on June 16, 1959, Superman was shot in the head and killed in his Los Angeles home. It wasn’t really Superman, of course, but George Reeves—the man who played him in the popular 1950s television series. His death was ruled a suicide, but there were (and still are) many who doubt that finding.

Reeves was only forty-five, had a beautiful fiancé, and had built a reputable and lucrative career in Hollywood.

But beneath the surface there were problems.

There were reports that Reeves was drinking too much and suffering from depression over the direction of his career: He felt he had been typecast as Superman and it was hurting his chances at other roles. Also, The Adventures of Superman was cancelled in 1958, which ended Reeves’ sturdy source of income.

According to the official police report, Reeves had company on the evening of June 15. At some point during the night, he left his guests and went upstairs to bed. He came downstairs a little while later, complaining that the party was too loud. Then he had a drink with his company before going back upstairs. The guests heard a single gunshot a short time after that.

It seemed like a cut-and-dried case of suicide until some inconsistencies came to the surface. Reeve’s fiancé, Leonore Lemmon, reportedly came running down the stairs after the gunshot sounded and asked the guests to say she had been downstairs the entire time. Then, there was the fact that there were no fingerprints on the gun and no gunpowder residue on Reeve’s hands. As the decades passed, a number of alternate theories began to take root.

One theory was that Lemmon either killed Reeves in a fit of passion or by accident. The accidental shooting theory has some credence because two other rounds fired from the gun that killed Reeves were found embedded in his bedroom floor, yet his guests only heard one shot. The gun may have discharged in previous arguments between Lemmon and Reeves, but this final time proved fatal. The reason why Lemmon and Reeves may have been fighting is related to another alternate theory.

It was rumored that Reeves was having an affair with Toni Mannix, who was the wife of MGM vice president Eddie Mannix. The latter was reputed to be an extremely jealous man who had mob ties. So, the theory goes, Mannix called in some favors and had Reeves killed.

The alternate theories were good enough to inspire an episode on the popular television show Unsolved Mysteries. The 2006 film Hollywoodland, starring Ben Affleck, also explored the possibilities surrounding the actor’s death. But unfortunately, since everyone involved with the case is now deceased, the complete truth will probably never be known.

The secrets of Superman’s death died with him, and possibly his killer.