A dead man lies on the floor with blood oozing out of his head. the victim is holding a gun and a tape recorder lies beside him.

Detectives come in, one of them picks up the recorder, presses only play button and the recorder starts playing immediately. it says "I'm tired of life and hence I've decided to end it!"

A gunshot follows the message.

But...

They start a murder investigation. Why?

Because if he actually recorded his suicide, the detective would have had to remind it to start from the beginning. He just pressed play and heard the everything till the gunshot. Someone else rewound the recorder; the murderer.


It wasn't suicide.



It was murder.

This isn't a puzzle. :-/

from your story,it seems the recorder stopped recording before the arrival of the detectives meaning someone else must have pressed the stop button. so,if actually the dead man committed suicide and did the recording himself,the recorder would keep on recording until the coming of the detectives who would first stop it before pressing the play button.
Hence,there is a murderer who must have stopped the recorder halfway i.e after the gunshot.
So,there is need to investigate.

Who stopped the recording?