You are going about it all wrong.
First, let kid do whatever.
Second: Blame inanimate object like video games or guns for behavior of child. Third: seek to place blame on self where it rightly belongs and find convenient scapegoat.
It works wonders for libs. They can scream all manner of trivialities and nonesense for years at a time.
It’s like catnip.
IBTZ
If the kid does something extremely bad there is the punishment of last resort.
http://www.freerepublic.com/focus/f-bloggers/2978191/posts
You can force him to watch Scott Ryan videos.