I definitely believe Kirkland is the prime suspect, he is suspicious and killed the associate of RJ because he was going to reveal his identity. However, it seems too easy; He is probably a high associate of RJ, there are a lot of
scenes that I thought were very interesting:
-The scene in the car with the FBI women
- The scene where he killed the guy in the hospital
-The scene where he changes the board of Patrick in order to know where he is in the RJ case
That's not a guess,
I'm definitely sure he has the power to be RJ