Something is wrong with that child. At very least, he has poor judgement and anger management issues, at worst, he is psychotic and fully capable of killing with purpose. He may have been jealous of the new baby. Now we have his 3 year old brother who was witness to all this carnage, and will have to try making sense of it all, unless his blocks the whole memory.
Interesting that you bring that up. Many years ago a friend of mine, who was a child psychologist, and I were discussing an incident about a 7 year old in California who murdered his playmate by bashing in his head with a rock.
My friend said that that abnormal behavior was now hardwired in that kid and that he would be a threat to society for the rest of his life.........