Writing this time not so much to submit a new theory, but to ask what should be a pretty obvious question.

Couldn't we have eliminated at least a few of the suspects on the list after S6E1?  I mean, we have the list narrowed down to 7.  Red John then kills Brett Partridge and Lisbon responds to the scene where she is knocked unconscious by Red John.  Red John goes so far as to call Patrick Jane from the scene contemporaneously from Lisbon's phone.

So we have a definite time and location for Red John (at the Partridge scene as he's calling from Lisbon's phone.  Why on earth wouldn't Jane and the CBI team check/confirm the whereabouts of the suspects on the list at that moment?  Even if done discreetly, it would not be too hard to check on some of their whereabouts.  Even assuming that Red John would have been smart enough to leave his cell phone somewhere far away from the scene (obviously knowing that it was being tracked).  You STILL ought to be able to check out the alibis of SOME of the suspects.  I mean, check to see if Tom McAllister was on duty up in Napa.  Check to see if Bret Stiles was even IN the states at the time.  Check to see if Kirkland was on assignment somewhere at the time.  Check SOMETHING. 

They just seem to let the whole investigation DROP.  They just say "Oh well.  It was Red John.  No need to even TRY to investigate." 

What's up with THAT?!?