I was told the day after the shooting, from an insider. That the mother and son were both MK ULTRA. The mother did something to warrant her death and they used the son to kill her and then had him go to Sandy Hook and kill as many kids as possible and finally himself. This was done to fuel a gun control debate, which of course is still on going.
I am not one for conspiracy theories, but the MK ULTRA program is a fact. They claimed they stopped it in the 80's but it is still on going to make clandestine super soldiers. The Jason Bourne series is essentially about the MK ULTRA program.