I find if unbelieveable that there was not a visit or some type of interaction/coordination before and during the sniper killings.
Our own CIA knows, I'm sure, but as has been pointed out by Laurie Mylroie and others, there are holdover factions within who seem to work against tying any domestic terror to Muslims of any stripe. Also, they fear having to reveal 'secrets' in court. So there may be known ties, but for these reasons the evidence will remain classified, IMHO.