A Mum wrote:7yrs old !!!!
Where were the parents.... he shouldn't have been out of their site, surely

I met a 7 year old who was admitted to our unit in the 1970s whose parents were in the habit of locking their bedroom door at night after they woke to find him chopping up the foot of their bed with a tomahawk in the midlle of the night. They also got rid of all such implements. Then one night they woke to find he had almost chopped through their bedroom door with another tomahawk he had picked up somewhere. That was how we got him!
He was in the unit about 18 months, and while he was abusive he was not violent. With time and tolerance the abusiveness settled too. He said "Hello" to me about 10 years later when he was working at a fruit stall in the Adelaide Central Market. As far as I know he never hurt man or beast after his stay with us....
You have to get in early. Unfortunately, I don't think any state in Australia provides facilities of that sort to do it anymore.