Traditionally in Australia at least, the person who is responsible for the death of a child is that childs parent or carer. In this case, the inclusion of a blanket tends to support that.
I sincerely doubt this is a Missing Persons Case.
Mum knows. Sad but statistically most likely.
I agree, SapphireSteel. Statistics everywhere, not just Australia, overwhelmingly support what you say.
The fact that seemingly the mother has never reported the child missing also suggests she is involved. It's a missing persons case only in the sense that we are looking for a mother who's conspicuous in her absence as far as this recent turn of events goes.
My only slight problem with the idea of the mother being involved is the degree of violence in the death, which is suggestive of a really sadistic killer, and not so much of a mentally-disturbed or post-natally -depressed mother who has killed her child in anger or frustration - an all too common occurrence.
I also have have a feeling, reading between the lines of police reports, that violence occurred after her death as well, although I admit I'm speculating there. If something awful like that happened, that would also be more consistent with someone outside the family and not the mother, as far as I have read.
But that only brings us back to the question of why the disappearance or death have not been reported by the mother, or anyone for else for that matter. It's all very confusing.