Red Taped

[Ginbottle]

When the police found the body of Professor John Smith, they found a tape recorder & gun by his side. On starting the tape they heard a suicide message, closely followed by the sound of a pistol being fired. Without hesitation the police handed over the case to the murder squad . Why?

[incitatus]

How did the professor die? he could have been stabbed after shooting at his attacker.

[andy hughes]

I presume the tape recorder had been switched off, which cannot have been accomplished by the Professor, and must therefore have been carried out by his assassin.

[Ginbottle]

The recorder must have been rewound, for the police to know straight away. If the tape had stopped before the finish, the could have been a power failure (mains or battery). The Prof. must have been shot or else the tape would be as useful as a sound-effects tape. If the tape was left to run, the sound of a person exiting would have been heard.