by this:

I watch a movie, it doesn’t matter which one. The maniac murderer is sentenced to death by hanging, but before that he must wait for two years in prison. - and -

Well, this is the same special law: 2 years in case of new circumstances. But suddenly it turns out that the maniac is not really him, but he has already been killed. And what will the investigators say:"Oh, sorry, the mistake came out?". The USSR had the same rules.