Sorry if it has already been posted here, but I thought this was interesting. I know that a few people had already wondered if there was a reason DD was left out of the obits, and I can't help but think we have an answer now. maybe
http://abclocal.go.com/ktrk/story?section=news/local&id=7877975
Quoted from the article noted in the above link..
"There are a couple of interesting notes from the family today. For the first time, the family has asked the media to stop referring to Jonathan's stepfather as such. They say, David Davis never acted like a father and was simply somebody who married Jonathan's mother. For the first time there was a little bit of public tension. The family refused to answer any questions about why Mona Nelson would implicate David Davis."
Given that AD and JF supposedly moved out because he slapped the boy, I would imagine the whole family is playing the guilt/blame game. I remember hearing once what percentage of marriages split up after the death of a child (even if that death was due to illness or accident). In a case like this, the odds would have to be even higher.