In the episode when PJ has a flashback, he and his father conned that woman with the sick girl. I believe that RJ has some connection to that girl. That might has sparked a grudge directed at PJ. It would also explain the attachment that RJ had to that blind woman.

I had this theory, that Chirstian Dos Santos was RJ, because he got the devil card in the episode where PJ first met the CBI, but Bruno Heller stated that RJ was on the list, so there goes my theory. Now I suspect McAllister to be RJ. He pretended to have a fear of heights to test if PJ had access to the info from Sophie. When PJ called him, he was right there, just behind him. He knew PJ needed help on the roof. He is the sheriff of a small town, who appeared the least among all the suspects. I bet all of my gummy-bears that he is RJ.

Hi guys!
There's something I don't understand..If Red John is really one of the seven, how come he is not doing anything and just lets Patrick closing in on him?
The real Red John that we know from the start wouldn't let this happen.
In the past he always killed everyone that was a risk to him, who could identify him. And he just sits around knowing that Patrick is down to 5 suspects and he is one of them?? It's just weird..

I know he is kind of fond of Patrick but surely he would kill him if he feels PJ is getting too close?? Obviously his own life is much more important to him than Patrick's life? 
I'm really starting to think RJ is NOT on the list and he is laughing about it all..

I only chose the sheriff because I would probably want him out of the 5 the most..

He is MAR
He is McAllisteR
Root of the verb to mar meaning to scar, impair.
Tom MAR: the one who scars, the red smiley face.
Jared Renfrew had information about Red John which he got from Orville Tanner when they shared the same jail cell.  
MAR is a possible nickname for McAllister, or Red John.  Something that people referred to him during his childhood which 
was continued into his early years of a murderer.

Spoiler Alert: Tom Mccallister is Red John.

The Red John Story: He grew up with an abusive father living with his family in a rural area, surrounded with wildlife.  Became fascinated with hunting animals as an outlet for the pain who his Father was inflicting on him at home.  He became involved with Visualize during his later years (17-22) and soon furthered his connections to people who were obsessed with pain, like himself.  His first public murder came at the Visualize farm when he was about 24 or 25 which is where he adopted the red smiley face.  He then began partnering with other troubled people which he connected with through his time at visualize.  His first accomplice was Orville Tanner someone that had a similar background as him, growing up in a small rural town. (similar to the town in Season 3 Episode 9 "Red Moon", also the character Todd Johnson's childhood was very similar to Red John and Orville Tanner.)   After Orville Tanner was arrested, Mcallister thought out a position of power in order to disguise his new identity and help prevent him from meeting the same fate as his partner.  Sheriff was the perfect position for him because it kept him in a rural area somewhere he is very familiar with.  This way he can hide in the shadows while committing high-scale murders between long intervals of time.  He became even more obsessed with the famous character that had become which is around the time he killed Jane's family after hearing Jane mock in on television.
 I believe his identity still remains unknown to both members of visualize and the tyger tyger group however both of these people know that Red John was once or is currently associated with their group.

Similarities-
Red John and Tom Mcalister are both left handed, but shoot their gun with their right hand. (Red John is a very good marksman much like Mcalister, which is due to his hunting background.... He began killing people with knives, his weapon of choice and developed his gun skills from shooting animals)
They both enjoy drinking tea and wear the same pointed cowboy boots.
They both have phobias (heights and partridges) Partridges are especially important because they are used as symbolism in the first 3 episodes of season 3.  

In the season 2 finale Red John saves Jane's life by shooting the copycat killers and in episode 3 of season six Tom Mcallister does the same thing by shooting the man taking Jane hostage.  This similarity was used by Bruno Heller on purpose to subtly built Jane and Red John's relationship as protagonist and antagonist.  

AND IF YOU STILL DONT BELIEVE ME GO AND WATCH THE PROMO TO SEASON 6 EPISODE 6 AND PAUSE IT WHEN YOU SEE THE SUSPECTS REACTIONS TO JANE POINTING HIS GUN AND TELLING THEM THAT ONE OF THEM IS RED JOHN.  Everyone is on the edge on their seat with looks of confusion and surprise while Tom Mcallister is completely comfortable in the same power stance seen in season 6 episode 2 when Jane tell Bertram, Reede Smith and Mcallister that Red John has made a mistake. (His hat is in his hand, legs crossed, head tilted). 

By combining several theories, here is my conclusion.
Red john is the seven headed dragon and the biggest head belongs to Thomas McAllister.
He is definitely strong, he afraids of birds( his phobia) and he was one step ahead of Jane.
Apart from the reamining suspects,
Kirkland's twin brother is the sixth head.
Brett Partridge is the seventh and the wounded head and I think he will reappear in the later stages.

Haffner will be killed off. Seeing how strongly Heller wants us to think its him.

Is like to say stiles, but like Bertram, he is too publicly known to go into Sophie Millers office as a fake identity.

Smiths only a pawn in the tyger group. Has no real significance otherwise.

Leaves us with Sherriff. Which I'm not thrilled about. But makes sense. He was there from the beginning and not around to make a mistake.

The odd thing is, in the voice of RJ he has a slight southern accent. Refer to season four finale. Was the only conversation he had with Jane. (In which both actively spoke). "You strung me along for a good long while". Sherriff has the only accent on the list.

Okay, so, still hoping for Minelli or the Sherriff. I'd be okay with Partridge, too...all I want is a great ending that ties it all together and stays true to Patricks character.

So...did RJ really try to plant the bug? I don't think so. I think it was the Tyger gang. PJ didn't surmise that correctly...because he hasn't quite defined the Tyger connection. Also, I don't think it was RJ who killed the PI...it was a Tyger guy. My guess is that they all have the red tattoo. PJ refers t it as leverage...makes me think he is using the existence of the tattoo to pull someone out of hiding...not sure how though...maybe one of the five real
Y is connected personally to RJ and the the fact that PJ is threatening their lives makes RJ reveal himself to PJ.

And are we sure the explosion occurs whee PJ has the suspects? Could it be another building. Maybe RJ attacking Lisbon.

Anyone have any thoughts.