The parents are living in a safe house and judging by the photo of the bunk beds in a bedroom, I assume there is at least one more child, also with them in the safe house? On that proviso, I think it is unlikely anything will happen to them regards the law, that's how our country is now, lax.
The Standard says 'a machete' and 'a quantity of bottles with matches attached to the necks were also found in the living room' and the living room appears to have become his bedroom. I don't believe these parents did not see or know about any of this in their home. If they had have called Prevent or the Police at this point, intervention would have been possible.