This is what Scott Rosenberg, writer of "Con Air" and "Gone in Sixty Seconds," among others, said in an interview at kidinthefrontrow.com about writing bad guys:
"As far as writing murderers, rapists, etc., I have always believed one has to find the humanity in even the most dreadful of characters. No one - not even Son Of Sam - is without a shred of decency; Ted Bundy had a mother who loved him at one point. If you can find an access point - a way to give make even the most unsympathetic of characters mildly sympathetic in places... Then you will have a fully dimensionalized villain."
I agree with that, and it's the opposite of what some writers do--they seem to think that the less human you make a villain, the scarier he will be.
I think the opposite--no "Dr No" will ever be as scary as couple Fred and Rosemarie West who (in real life) tortured and killed a series of young women in their neat little suburban home.
They looked just like the people you see in the supermarket every day, they had friends and relatives who loved them, yet they were capable of cruelty to a horrific degree. Now THAT'S scary.
