I think Kirkland is RJ. After the last episode's ending, and his obvious need to find out everything that PJ knows about RJ, I would conclude that he is either working with or for RJ, or is RJ. Being in Homeland Security, he's not only close to PJ and the entire team, but also has a lot of connections. And the RJ smiley face from the episode the Red Barn could have been from him as a kid, or more likely, the original RJ is or was his mentor. RJ has to have someone to carry the torch when he's gone, right? And, if not, it's a well-known fact that he does have accomplices.