Tutankhamun's mummy
Detective Michael R. King and FBI profiler Gregory M. Cooper came together with an actual Egyptologist to form their own theory which was that Tutankhamun was murdered. With the use of forensic evidence and their extensive backgrounds in criminology, they came to the conclusion that he was likely murdered by one of his closest advisors, Ay. Ay did succeed Tutankhamun on the throne, so they used that as the motivation for the murder.
Thutmose IV
Recently a surgeon at Imperial College London analysed the early death of Thutmose IV and the premature deaths of other Eighteenth dynasty Pharaohs (including Tutankhamun and Akhenaten). He concludes that their early deaths were likely as a result of a familial temporal epilepsy. This would account for both the untimely death of Thutmose IV and also his religious vision described on the Dream Stele, due to this type of epilepsy's association with intense spiritual visions and religiosity.