I’ll add one thing: little Mr Murderer got raised in a hell of a lot better economic environment with wealthy physician daddy than me and my seven younger siblings did And I bet he didn’t move twelve times by the time he was 18 like I did.
We don’t know if he was a real rat or if the sister was really obnoxious or what. Not that that would excuse him.
He looks like a relatively normal kid here: http://thenypost.files.wordpress.com/2013/12/sibling-murder.jpg
The original article mentions the two fighting often, sometimes violently.