I don't want to derail the thread, but in the Meriweather scenario, it's something we've seen before: you have a fight and some tough guy has a gun on him and shots get fired. Not to be flippant, but it happens. Not saying it makes it less of a crime, but it's not premeditated, it's usually some idiot running on instinct with some mob mentality thrown in. It's hard to tell if the intent is to kill or frighten or what. In this specific case, we don't know enough. Either way, it's just a different dynamic.
As for Roethlisberger, there really isn't anything more heinous than rape as far as I'm concerned, and per the details of that night's event, he - whether the AG thought they could convict him or not - most likely committed the act.