A lot of crimes like that are committed by mentally ill parents.

A schizophrenic woman murdered several of her children. God told her to do it.

It's not always their fault...chemical imbalance in their head. Seemingly real hallucinations. Voices. I mean, who is to say that this person is bad or good? It's a shitty thing that happened, but the real "SICK" and "SCARY" part of it comes with the media's leaving out details and even demonizing the person in situations like this.