Like many forms of sexual deviance, pedophilia once was thought to stem from psychological influences early in life. Now, many experts view it as a sexual orientation as immutable as heterosexuality or homosexuality. It is a deep-rooted predisposition — limited almost entirely to men — that becomes clear during puberty and does not change.
[Some] pedophiles are “good people who are struggling,” said Dr. Fred Berlin, a psychiatrist who heads the Johns Hopkins Sexual Behaviors Consultation Unit. “They’re tortured souls fighting like heck not to do this. We do virtually nothing in terms of reaching out to these folks. We drive it underground.”
Here is a good article about some emerging science relating to pedophilia and how society might deal with pedophiles.