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.
KV62
Tutankhamun's tomb had been entered at least twice not long after his mummy was buried, and well before Carter's discovery. The outermost doors of the shrines enclosing the king's nested coffins were unsealed, though the inner two shrines (three and four) remained intact and sealed.