10 Chilling Doctor Who Unsolved Mysteries
3. The Murder Of Peter Arne
The Fifth Doctor serial Frontios features a character called Range, the chief scientist of a remote human colony.
The role was played by William Lucas, but it was originally earmarked for British character actor Peter Arne, perhaps best known for his appearances in the Pink Panther films and The Avengers TV series.
Arne attended a costume fitting for the role on 1 August 1983, before returning to his home in London. Soon after, neighbours reported hearing a loud argument in his flat. When his home was searched, Arne was found dead, having been bludgeoned by a stool and a log of wood from his fireplace.
A police investigation concluded that the perpetrator was Giuseppe Perusi, an Italian schoolteacher. However, they had no idea why he'd done it.
Perusi and Arne did know each other, but nobody knew why they were arguing, or what drove Perusi to commit murder. This aspect of the case remains unsolved to this day.