I guess, and it is Only My Opinion,
that his parents were helpless, overwhelmed and terrorized by their son.
The older he got, the more insane and menacing he became.
He attacked his own father once,
when dad tried to cut AR off the Internet.
To be fair to parents,
they tried to get help.
They did.
They called Police to home, they asked for help.
But if institutions couldn't control him,
the parents could do less.
He had his room, but seemed to grab a living room too (and it resembled a pigsty with all those boxes).
This is terrible.
I still think that he should have been put in some correctional facility for troubled youths after a hockey stick attack at school.
But who decides about it in the UK?
In my country it is the task of Family Court.
It deals with violent/troubled minors and parents who cannot cope.
Because it is obvious to me that his parents didn't cope with him,
they were helpless and seemed terrorized by this demon.
JMO