ive read many theories and many of you have overlapping thoughts about who RJ is, i dont want to use this post by saying who i think it is i want to respond to a  theory some of posted

some think that maybe RJ is someone from PJ past who has a grudge against him, his father, maybe his brother of even the new introduced Sean Barlow.  

So you say  the real underlaying reason of the tormenting agains PJ is his connection with PJ in past, but why does Red John appear after the slandering of PJ? Red John only killed his Wife and Daughter after PJ said those things about RJ on TV.

RJ has killed many people before PJ said those things about RJ on TV so the theory about RJ is connected to PJ's past just doesnt make any sence. If RJ really is someone from the past that has a grudge against PJ, why wouldnt he attacked PJ earlier?