@Health Well, I googled the case you’re talking about. The only people who are claiming it’s Satanists is some weird paganist blog. All the more mainstream (and fringe) news sources simply list it as an unsolved mystery. The links to the (10 year old) allegations aren’t even working anymore.
Yes, I sound like that last line. Probably because it’s true.
Satan worship isn’t a huge thing in the US. Those that are Satanists are mostly just pagan idolators and not death worshipping murderers.