I'm a Yean, You're a Witness?

The formula for these shows, go to the obvious, a culprit first, ok. They say, i was never even there. Find out a piece of evidence that places them at the sceneo and go back to the person. Witnesses only get like one scene. And whoever is the biggest star on the episode always did it because they want that juicy scene at the end where they're like, o of course i did it.