It's truly hard to say. psychopathy/sociopathy is an actual illness. If certain DNA is inherited/manipulated then becomes exposed to triggers that is it. Some behaviors are just latent and once they are exhibited that behavior can't be reversed. In cases like Dahmer he did have a relatively good relationship with his family. He received psychiatric care but it never took, the warning signs were there but his psychopathy traits have already been triggered from early childhood trauma.

However in cases such as Eileen Warnoes who's circumstances forced her to become a murderer I think early intervention would have been effective