Shadows On The Stairs, another movie with a twist right at the end

A 1941 black and white movie, it’s based around a guesthouse in London where several of the lodgers are murdered.

The police get involved and one by one the culprits are caught.

One man gets away with it, as the police think someone else committed the crime.

Then, he confesses and you think, why did he do that.

Immediately, we find out why.