Tut was not, although it is believed by so many, was not murdered. At least not by a crack on the back of the head. I believe that the dent found in his head was caused by Carter and his team when they found Tut’s tomb. Basically, not caring about the mummy itself, Tut’s body was ripped apart when they searched for gold and jewelry.
Through DNA and CT scans, they have a pretty good idea on how Tut died. As of yesterday, people are saying that Tut most likely died from falling off his chariot, either during a battle or while he was out hunting. After his fall, he had hurt his leg and through that, he either died from malaria or gangrene. It might have also been internal bleeding that caused his death. Either way, the scientists are convinced that he was not murdered. Though, if one thinks about it, the fall from his chariot might have not been an accident. Sure, it is possible it was, but on the other hand, if someone wanted Tut dead, making him fall off a chariot would be an easy way to do it and still say it was an accident. I am just reporting what the scientists are saying and then adding my thoughts to it. 🙂 Hope this explained it for you and sorry it took so long!