Who is Nelson Muncie from The Pelican Brief and what is their importance?

Nelson Muncie is a rich, reclusive Florida industrialist who idolizes his 12-year-old niece, Muncie snaps when she is raped and murdered by Buck Tyrone, who confesses in writing, is convicted, and sentenced to death. Justice Abraham Rosenberg, however, writes a convoluted Fifth Amendment decision that throws out the confession. Muncie apparently has Tyrone and his lawyer killed and has indicated he wants Rosenberg dead. This motivation closely parallels what comes out in the "pelican brief."