Dear Ian Zochling
The story you write about might be true but it's impossible to say.
People who read palms and tell fortunes and so on are often very good judges of character. The palmist probably guessed that the prisoner couldn't possibly be a murderer and so there was a good chance that he would be freed.
Who knows. Perhaps there is something in chiromancy that we don't understand yet.
But probably not. It was only a hundred years ago that lots of people thought that phrenology was the answer. They thought that the shape of your skull and the bumps on it told all about what you were like. That's because they thought the shape of the brain affected the shape of the skull and the shape of your brain showed who you were like.
We now know that was nonsense. The brain is a zillion times more complicated than that. Probably palmistry is just as silly as phrenology.