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.
Fall of Tenochtitlan
Cortés attempted to parley with the Aztecs, and after this failed he sent Moctezuma to tell his people to stop fighting. However, the Aztecs refused. The Spanish asserted that Moctezuma was stoned to death by his own people as he attempted to speak with them. Three stones hit him, one of them on the head, so cerebral hematoma is possible. Moctezuma refused all medical help as well as food, and died soon after the attack. The Aztecs later claimed that Moctezuma had been murdered by the Spanish. Two other local rulers were found strangled as well. Moctezuma's younger brother Cuitláhuac, who had been ruler of Ixtlapalapan until then, was chosen as the Tlatoani.