It is Patrick's father.

Let`s see. From what has been shown to us until now, we can
agree that:

Red John hasn`t had anything to do with
Patrick until the moment when he felt offended by Jane in the media and
killed his wife and daughter. We know that RJ is a serial killer who
started “working” in 1998, but he
didn`t do it because of Jane, as he had nothing to do with him before
Patrick`s interview on TV.So Red John began having an obsession for Patrick because
of that incident. He was probably surprised, intrigued or annoyed by
Jane`s intelligence and capabilities of reading people, so he decided that
murdering his family is not enough. He wants to make PJ his disciple, he
wants to manipulate him, and to make him understand that even if he has a
gift (of being a mentalist) Red John is way above his powers. He wants to
make Jane accept the fact that Red John will always be one step aside, and
that his desire of revenge is hopeless. Given the fact that
killing PJ`s family was not enough for RJ, he decided to dedicate part of
his life and work messing with Jane and “testing his powers”. He has
friends everywhere, even in the CBI and his intelligence helps him always be
in the right place at the right time. More than that, Red John never lives any traces. How weird
is that? No one sees him, no one wants to speak about him. So we have a really sick and intelligent person who
has the resources, the power and the abilities to make Jane`s life a
leaving hell. He has many tools (such as Lorelai Martins) who, for some
reason (they are probably sick persons, too) are manipulated by Red John
and do terrible things to “show their respect for him”. Are they hypnotized?
No. If they were, Jane would have figured it out instantly. So how is that
possible? How can someone make another person kill, torture other people or
even kill herself for the “holly master”?

My point is this: Red John wants to
teach Jane a lesson. He isn`t anyone from Jane`s past, but someone who wants to
make PJ understand that he is nothing but a liar, a clown who does nothing but
fooling around. He took his family away, he took Kristina Frye, and he wanted
Patrick to kill Lisbon (the only person that he trusts and, probably, is in
love with). He wants to took from PJ everything he loves, so, in the end, Jane
can understand that messing with Red John is not an option.

Interesting fact: Generaly, Red John kills the persons who dare to
speak publicly about him, but in PJ`s case, he decided to  murder his family instead, and to continue
keeping an eye on Jane`s life.

I just would like to say that i love this site but i hate a couple of things.
First ... That jane is in the header as one of the most suspected persons ... Please, stop choosing jane as a suspect it makes us look dumb and dumber ...
Second ... If heller already told us that RJ is one of the 7, if heller told us that RJ is a man, if patrick told us that RJ is a man ... Why do we see continuously Lisbon, Van Pelt, Rosalind Harker and Kristina Frye as suspects?

I'm not going to go into speculating about who Red John is, because I think there are enough clues for almost every person on the list to somehow fit the role.  I just wanted to point out that it wouldn't really be much of a feat to get into Patrick's deepest psyche the way Red John apparently did on the last episode.  If you'll recall, Jane was in a mental hospital for something like three months after his wife and daughter were murdered by Red John.  It doesn't take a huge stretch of the imagination to believe that RJ was either at the hospital during that time, or had someone inside gathering information that he could use later.  It seems plausible to think that at some point, Jane tried to return to that particular thought while he was there, in order to cope.  Jane said that he never told anyone about that memory, but that doesn't preclude the possibility of him muttering to himself, or even hypnosis.  We can say that Jane may be impervious to most attempts at hypnosis, because he is acutely aware of himself and others, but while in the hospital, he was vulnerable at best, and could have been taken advantage of by RJ.  

I'd also point out, that even if we ever get to find out who RJ is, I think the more interesting question is why he does it.  Everything to this point is mostly speculation: maybe he has a problem with women, maybe he just likes having power over others, maybe he's just a deranged lunatic who gets pleasure from murdering people.  I think that after everything is said and done, it will be far more interesting to get a glimpse inside of this guys head, than to just go, "Aha, so he's the one!" and be done with it.  I've been pretty happy with how the show has gone thus far, so I think that they will probably deliver a satisfactory conclusion to the Red John saga.  Will it go on after Red John?  Who knows...  

I believe that RJ is someone from PJ's past. According to the last episode it was revealed that RJ has 'real powers' so I am assuming that is someone from his childhood/puberty years that was close to the him and his father while they were performing their psychic acts. 

I believe RJ is someone around Jane's age or slightly older that he had very strong powers when he was young but PJ somehow 'stole the show' and he became extremely famous. One more argument that I believe enhances my suspicion that RJ somehow is linked to that specific part of PJ's past is that, at the last episode it was said that RJ killed a happy memory that nobody knew about. I believe someone knew about it and that is RJ. I am assuming that PJ was hypnotised in the past by RJ so that the latter could prove his power to the first one and he traced that memory while PJ was under hypnosis. That memory and many others of course.


P.S I was so certain that RJ was Shettrick at some point because of the male characteristics she has, and also has red hair, and also her voice was weird reminding me RJ's voice. So I thought it was RJ dressed like a woman justifying that way the contradiction in his name Red (feminine) John (male). But then I thought that RJ doesn't seem to be someone who has direct involvement with the CBI or FBI, but he has lots of accomplices over there. He is someone external but someone from PJ's past.

I think Rosalind's physical description of RJ can be ruled out, for two reasons:

1. PJ's list of suspects (if it is assumed to be complete and real) does not strictly adhere to how Rosalind described Roy to be.

2. When Lisbon asked if she was on the list, PJ said she isn't, because he'd call what they have a friendship, and not because she's female, and RJ is male, according to Rosalind. 

Now, I'm not saying that RJ can't be the way Rosalind described him to be- I'm just saying Jane doesn't trust her description and isn't bounded by it.

I also think the list of suspects is not complete, again for two reasons:

1. We are all forgetting about the "He is Mar/Man" clue written on the wall when RJ's accomplice died. Other than Ellis Mars, it doesn't exactly point to anyone else on the list.

2. RJ is a very central part of the show, he's almost as much important as PJ. But the suspects, i.e. RJ's assumed alter ego/real identity have hardly ever been seen to be interesting, or of any importance to the storyline beyond a few things here and there or a few episodes. RJ has to be someone who has a connection to Jane, in my opinion, because otherwise, it just falls short of the show's intriguing dramatic twists.

Another thing: correct me if I'm wrong, but when PJ gave the interview that got his family killed, he was already approached by police to help catch RJ, right? Given how connected RJ is, and his obsession with PJ, what are the odds that he himself had set that up?

I'd like to believe that RJ is someone from PJ's past, simply because he is so obsessed with PJ. RJ killed the other serial killer who mocked him on TV, but PJ, he's kept alive and has been toying with, even deviating from his MO to mess with Jane. 

I think it'd be someone Jane shook hands with back in his own life, but forgot to factor in, just for the shock factor. RJ's revelation is the climax of the shock, it has to be important.

If RJ is indeed any one on the list, PJ can just shoot him and get on with his life. He is not even close to any of these people- in a love or hate way, their death is not going to affect him in any way. But RJ, I'd like to believe, would pose a question to PJ.

Anyone agree?

Something I thought didn't make sense.  At the end of the first season finale the guy that Jane shot said that red john 'wanted you bad'.   For what???  He has his chance to do whatever he wanted to do to Jane at end of 2nd season finale but does nothing.