Has the case been on the local news in the evening? Often those without internet, or much interest in internet, make a point to watch the news.
The way LE is behaving, I am not really feeling that awareness is their issue, so much as determining if they have any real suspects on their hands, with actual evidence. But if they do not, then they could be missing some other angle by focusing, allegedly, on two men. Granted, I believe this focus is likely justified if not provable, but especially in a circumstantial case, they may need to prove they looked elsewhere. Without appealing to the public on a regular basis, this may be more difficult to show, IMO.