Dr. Miller was staying with his cousin, Alfred, in Alfred’s lakeside cabin. They were setting up Alfred’s will. Since Dr. Miller was Alfred’s closest living relative, much of Alfred’s estate was being left to him.

One day, Alfred went to Dr. Miller very upset. “Doctor,” he began, “I have just found out that an old enemy is out to get me. He is coming very soon. Where will I go? Where can I hide? If he finds me, he will surely kill me. I do not have time to leave this cabin and hide in the woods.”

Dr. Miller thought for a moment, and then grabbed a 5′ long bamboo fishing pole, with a diameter the size of a quarter. “Alfred, follow me out to the lake. This lake is 4′ deep. If you lie on the bottom of the lake and breathe through this pole, your enemy will never find you. I will be in the bulrushes with a shotgun, and I will shoot him when he comes. I will swim down to find you when he is gone.”
Alfred thought that was a great idea and went down in the lake with the bamboo pole in his mouth. A few hours later, a ranger passed by. He found Alfred’s body. Dr. Miller told the police of the circumstance, and that Alfred had probably panicked, and died. Police arrested Dr. Miller on the charge of murdering Alfred. Why?