Protecting you child must the paramount thing for us as parents,maybe from harmful situation and and others, that is exactly how john felt when he saw that his lovely daughter , who is a happy and lovely girl is no longer happy and the way she does things has change
That is when everything go downhill that made john to put drastic measures into play,he neeeded to know what was wrong with her daughter and the reason why she cant tell him what was going on with her.
There is nothing like parent so that is why john has to do what he did, what of if it was your child ? wont you do the same. this story of john and is daughter was a perfect example.