Revered in movie-land, the topic of many a blockbuster, what exactly is the appeal of the serial killer?

Looking back at crime files from around the world, the average serial killer, if there is such a creature, is male, articulate,plausible and in some cases, downright charming. These are essential tools of his trade, how else would he ever manage to get close enough to his victims...especially when everyone knows there is a serial killer on the loose?
But what is it about the serial killer that attracts us, holds our interest?
Most of us, whilst fascinated by the extent of the crimes, are repulsed by the details and yet we crave more...more information, more details...even more pictures. We feed on the gore and the media respond to our feeding frenzy with increasing fervour, providing us with fact and fiction in unequal and indistinguishable part.
The serial killer as 'Entertainment Value', an unpleasant thought? What is it about these crimes that make us want to pay to watch the horrors played out on a screen at a cinema or worse still, to bring them into our homes? What makes us turn the pages of a well thumbed book in search of details for our fertile imaginations to weave into pictures in our heads...and in our dreams?
What makes a serial killer? Are they born? Are they Mad or 'just' Bad? Who can say...but the most frightening thing is that they are human, just like you and me, and that fact suggests perhaps we all have the capacity for 'evil'?
Humans are, after all, very base creatures indeed. What is it. for example, about the human that makes him believe in his own invisibility whilst stopped at a red traffic light? What is it than then makes him decide to publicly lunch on the contents of his nostrils? What would make him want to do this? A desire for salt?
Disgusting maybe, but true ...and perhaps the serial killer, smiling at him from the car pulled up alongside in the next lane, finds his actions abhorrent. Maybe just abhorrent enough to.....