!!!Spoiler Evidence!!!
Did you ever figure out what was the big clue at the end of Season 6, Episode 1 Desert Rose? My original guess was the close up of the knife and that it was a surgical hook knife and something that Brett Partridge might have had in his tool kit. Well, right about knife being the clue wrong about what type of knife!
Truth is the bloodied knife that Red John is toying with after painting Lisbon's face is a hunting / buck knife with gut hook. See for yourself, Red John, whom we know likes to hunt deer, probably bought it from the link below to Sears! LOL
Good hunting!
http://www.sears.com/shc/s/p_10153_12605_SPM7265451005P?sid=I0084400010000100600&aff=Y&PID=3300089&A...