I don't know. I just checked his Wikipedia page and saw this though. It doesn't answer your question, but damn!
In 1985, he [Kercheval] became a partner in the Old Capital Popcorn Company. The business thrived at first but the partnership soured in 1988. The financial issues and other conflicts led to a 1989 armed rampage and suicide by one of the partners on the Dallas set.
Tell me about it. I did a WTF when I read that, too.
Poor guy, he just looks so pale and wizened. My mother and I were shocked when we first saw him.