I’ve always believed that at least some people, and especially a lot of serial killers, are just flat out wired wrong. I think a medical study recently confirmed that. But the point is that some people just can’t be rehabbed or ‘fixed’. They are what they are.
I agree, and whether they're wired wrong because of their genes, events in early childhood, or (most likely) some combination of the two is really irrelevant by the time you're dealing with an adult who is beyond redemption.
Unfortunately, the nature-nurture debate has been politicized to the point where people can't take research like this at face value. The Left bears most of the guilt for this, because research on the heredity of human behavior, intelligence, etc. runs counter to their obsessive dogma about "equality," while the Right generally accepts these ideas. However, sometimes the tables are turned. The Left pounces on hereditarian explanations for behavior (e.g. homosexuality) when it suits their agenda, while certain elements of the Right turn into anti-hereditarians on this issue.
In reality, these questions shouldn't depend on politics at all. Either there's a genetic basis for intelligence/anti-social behavior/deviant sexuality or there isn't, whether it's politically convenient for whatever group or not.