Yep, we the public will be the last to know.
Law enforcement always knows more and doesn't disclose details of their investigations for a variety of reasons. Everything from not wanting to tip off any suspect, or do anything to compromise the future legal case, to not wanting to hurt the family, to protecting people's privacy/safety to having to wait for information from phone companies and Internet companies and surveillance cameras in the area, and all that kind of potential evidence.
And then there's the forensic side of these cases where they send off items for testing but the public is not privy to the results of everything. It comes out at trial.
Many people think these things take no time at all (just like an episode of CSI) and everything should be back in a matter of a few days. I don't think real life works that fast.