When something is as common among humanity as pedophilia, of course there will be some people for whom pedophilia and psychopathy cross paths.

It should of course also be noted that psychopaths are not necessarily evil. A few pursue noble goals out of an intellectual understanding of the world, and many more may be selfish but do not go out of their way to harm others. I suspect that there are also degrees of psychopathy - that some have no emotional affect at all, while others merely have their emotions muted, or perhaps some emotions are full force while others are missing entirely.