I kind of wonder if the local media has stopped covering the case because they were shunned by D&J when the case was hot. Even when D&J talk, like with the debit card story, they seem to just give it the bare minimum of coverage. Also, local media has sources within LE so if they wanted, they could get some information.
There was a press conference back in October where a local reporter asked, "Why won't you talk to us? We will be here when the national media leaves." I didn't hear the question, but the person who was posting about it said that the local media was pissed. Then, whenever I watch/read anything about the case from the local media, they always mention about the deal the parents have with national media, how they won't talk to them, etc. Locals also said that the local media was always very nasty and rude to the parents, so we know that they don't like them.
It makes me wonder if the local media decided that since the parents decided they weren't important, they wouldn't act like the parents were important. If the parents talk, they'll write an article, spend 2 minutes on TV talking about it, because they are notorious residents of KC, but no more obsessing over the case.