Here is what you have to do. You have to throw a ball as hard as you can but it must return back to you even if it does not bounce at anything. Also, you have nothing attached to the ball. There is no one on the other end to catch that ball and throw it back at you.
A man is found dead with a knife in his back When the investigation is done. A chair lays beside him and the forensic team finds moisture around the body.