I can not believe that little 8 year old boy could Kill one grown man, and then just blantly shoot another man. At least one of them would have stopped him. I mean He is an 8 year  old boy. I have a grand son that is 7. I just cant see it. 
Has the father been checked out seems that a newlywed would want some other man living with him and his  "New Wife". 

Seems strange to me. Has any one check out the relationship between  the  father and  his  roommate.

If there was something going on there, Well that brings the   New Wife in to the picture.

She could also be considered a suspect.   She defiantly not a good step-mother.  I have a step-daughter and believe If her father wasn't available to be with her in a case like that I would be there to protect her  rights.

If you read this, don’t just take my words. Check it out for yourself.   When you have make your feeling known.