Why are we obsessed with Serial Killers and their phycology?

Just an open question, and by open I mean OPEN

Feel free to be totally honest,

It sounds incredibly weird, but I myself have wondered on this question, and I think the real answer is that "normal people" through their lives so often are able to hide who they really are and how their brain functions. We are quite literally "normal" because we can hold back on impulses that guys like BTK would not be able to

Prehaps it's the fact that serial killers act like a mirror to us, and thus allow us to reflect on our own phycology. It's intresting to compare how you yourself interpreted a series of thoughts.

I don't know its just a weird feeling learning about all of this, because in the end when learning and watching these programs we are considering the human elements of these monsters and thus are relating them to ourselves