I don’t disagree with the concept that not all who commit violent acts without remorse are mentally ill in the clinical sense, but I want to clarify that I was in no way justifying the behavior, merely seeking to shed some light on it.
People who have those unpleasant characteristics could conceivably still benefit from some sort of treatment. It wouldn’t be meant to punish them, but hopefully to make them more capable, upright citizens once they are released (if that is the case).
I suppose this crosses into the whole punishment vs. rehabilitation concept, since most people just want to bury these sorts of criminals in jail and not treat them. The violence is so overwhelming that it’s second nature to write it off as “crazy” and not dwell on the fact that the potential for violence lies dormant within all of us, if we’re pushed far enough.
The success rate for this treatment is quite depressingly low, however. Medications are not effective, other than causing enough of a stupor to suppress the behavior. Cognitive behavioral therapy can hold some promise, but the person must be willing to honestly engage in the therapy, and must want to change. Being compliant with therapy will get the patient nice write-ups from the therapist to the parole board, but doesn’t reduce the risk of future bad behavior.
As others have mentioned, the girl was 12, so PND can’t quite apply in this case, though I do think it’s seriously under-examined and a source of shame and pain for many new mothers.
Tjat being said, I think it’s possible that the girl’s age was a factor– puberty is probably right around when a seriously needy woman desperate for male approval might start seeing her daughter as a rival rather than a child.