As I found out, no they can't tell why, but they can theorise how. Two scientists are convinced that Ötzi was killed by someone he knew. That he was shot by an arrow in the back. But that didn't kill him. They think that he was either killed with a blow to the head with a blunt object, or from hitting his head on a rock when he fell over. Scientists lean more on the side that he was killed by a blow to the head.

Why was Ötzi killed/murdered? Can they tell?