Do I really have to go into why this attitude doesn't do any good...it might get graphic. If he's been diagnosed as having some kind of disorder, chances are that disorder plays a major role in these violent 'tantrums' not sure tantrum is an accurate term per say seems like something more serious than that.

Either way the kids 9, not entirely irredeemable. Also I'd think most parents even if they did adopt the child would have a hard time just giving them up even with serious issues like this.