Mr Zuckerman wasn't a man of many words on this, but what he did say was very clear. You need to develop your villain as well as you do your protagonist.

Villain must drive the problem. I'm sure we've all read the novel in which luck plays a very active role, perhaps a character herself. Don't do that.

Villain must have a motive. It must be clean, clear, good, and ideally unselfish.

Give the villain redeeming qualities. In Silence of the Lambs the antagonist is skinning his victims but god...