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.
KV54
One of the critical finds from KV54 was a piece of linen marked with hieratic text saying "The good god, Lord of the Two Lands, Nebkheperure [the prenomen of Tutankhamun], beloved of Min. Linen of year 6." Recognizing that KV54 did not represent Tutankhamun's actual tomb, and that it "did" signal the existence of a yet-to-be discovered tomb, archaeologist Howard Carter, who would eventually find the real Tomb of Tutankhamun, corresponded with the Metropolitan's Egyptological Director Herbert Winlock on this subject in 1915.