A Joke

This is crime story. Five friends lived in a room, Namely MAD, BRAIN, FOOL, NOBODY, SOMEBODY.
One day SOMEBODY killed NOBODY. At that time BRAIN was in bathroom, MAD called police.
MAD: Is it police station???
Police: Yes, what is the matter??
MAD: SOMEBODY killed NOBODY.
Police: Are you mad?
MAD: Yes, I"m MAD.
Police: Don`t you have BRAIN.
MAD: BRAIN is in bathroom....
Police: you FOOL...
MAD: No, FOOL is reading this joke...