Ok, after watching the last episode, it threw my theory of it being Kirkland out the window. I will most definately be very disappointed if it turns out to be a organization and not one person. I would still like to believe RJ is PJ him self, that would be a good ending to this section of the series. I agree with a previous comment on here, firstly about Cho and Tiger Tiger, he could be involved. I also think it has something to do with Rigsby and Van Pelt. They are leaving the show, so what will happen to them?
Also anyone else notice that when RJ kills his victums, he slits their throats, however in S5E16, when they find Lorelei at the end her throat isnt slit?? Curious isnt it? Maybe she isnt dead??
