For someone demanding tolerance you are awfully intolerant towards differing opinions.
Being sadistic, entititled, or thinking you are above everyone else can all be the result of someone’s mental illness.
I do not believe in good and evil, not a religious person. While the transition is gradual, we normally understand a physical and psychological alteration as an “illness” when it causes the affected person pain / discomfort / limitation or when it makes living in current society close to impossible.
Wanting to kill babies certainly fits that definition. Whether she was actually brainwashed or mindcontrolled by aliens, we do not know. But additional possibilities don’t rule out mental illness as an option.
I also didn’t meant to give the option to change to the murderer, but that there is the possibility for humans to get rid of murderers, for example, when we find a way to cure all kinds of extreme mental illnesses.