Here's an interesting comment from a July 16, 2008 story that, if true, shows police truly were zeroed in (incorrectly, we now know) on BC early on:
I work with someone who said her best friend was down at the police station yesterday getting her P.I. license. She mentioned to one of the guys there, "You guys have some action going on in Cary, huh?" He nodded. She said, "I think the husband did it." To which he replied, "We know who did it."
The police are carefully crafting their case. It is important that they be able to put this person away, and in the meantime they cannot damage their case, so they must be tightlipped and protective of their information. It doesn't mean they don't know anything. In fact, the family probably knows everything they know, and did not want Brad at that news conference. If he is guilty, and they know it, they could not stand to be in the same room as him, faking solidarity. I think that is why he was not there. The family did not want him there. But the police can't tell us that.