OK. Nancy Grace is a prosecutor. She's been trained to be a prosecutor. So, combine that with the fact that she suffered a horrid personal tragedy in her life (one NO ONE should ever have to go through, by the way...not even her).
Thus, her reaction is to act like a pit bull.
And her ethics have suffered somewhat, according to Wikipedia (scroll down to Appellate Section). To me, the questions about ethics are the worst things you can say about an attorney...civil, criminal, or prosecutor.
CNN has put an angry woman on the air simply to exploit news situations for ratings. Watch Greta on Fox News instead...she seems much more personable than Nancy Grace-less.
Mike