Maybe there is someone being protected that we haven't thought of.

And that someone is John's multi billion dollar employer, Lockheed. As much as John Ramsey is trying to redirect the police and media away from himself and the Ramsey family, he barely mentions his employer.

But on the day of the murder he was talking to his HR person and the corporate lawyer from Lockheed. They were the ones who advised (or insisted) that he lawyer up. Was this for his benefit or the company's? This must have been a potential PR nightmare for Lockheed, to have one of their CEOs involved in the death of a child. So he had to do everything possible to cover it up. It seems to me that the police and DAs office may not have really wanted to find the Ramsey family culpable, for it could have been politically unpopular. Anyway, this is just speculation.