Trial process

Our trial process while good is not perfect. Sometimes people are convicted and imprisoned and then the verdict is overturned. What happens when a person is convicted? Do they have any rights? What are they? What happens when a convicted person gets the verdict overturned? Are they innocent? What role does Habeas Corpus have to play?

Have you ever heard of anyone who has had their conviction overturned? What happened? Do you agree with the process? Why?