The most obvious suspect is Bob Kirkland. In fact, I think it's so obvious that many of us have gone in a different direction thinking that Heller would never make it that obvious. Then there's the hospital scene. If Kirkland is looking for RJ himself, then why not question him about RJ before killing him? I think that scene is meant to throw us off, while at the same time building the suspense around Kirkland. If he turns out to be RJ, it will be explained why Lennon didn't recognize him, which could be for a number of reasons. Kirkland could merely be working for RJ, but he has only interacted (on screen anyways) with Bertram, and he seemed to be the higher power in that scene.
Kirkland looks, acts, and sounds like he could be RJ, more than any other of the suspects. Haffner was served up to us last episode, but if you watch his past appearances, he has been outsmarted by PJ, and talked down to by Bertram. In fact, before this season, Haffner had done nothing to make you wonder what he was up to, other than his involvement with Visualize.
Then there is the Kirkland handshake scene. The only one of the seven suspects to have their initial handshake showcased dramatically on screen, complete with ominous music. Finally, Kirkland is one of only two suspects not to have appeared yet this season, which sets him aside for something. We'll see.
