How do rapist and pedophiles work? I can kind of get the sex thing being like a release or whatever. But what about the power aspect? What is going on in the brains and chemically in the body?

If it is a power thing how come pedophiles don't get off on watch people with power humiliating people lesser than them? How does a rapist keep walking with a hardon? At one point the brain has got to tell the body this is really fucked up but I am asking on a scientific level. I got alot of questions. Thank you in advance for taking this serious. I can expound on my original questions if you like.