I am absolutely sure that Patrick Jane is Red John.You know maybe it is far from to be true but it is true .I have sorted out many events and causes and reached this result but I did not find out the motive and it is because of the information lack of R.J's past .I assure you there will be more in season 5 .Did you ever noticed that there is a huge messed up when the case is about R.J ?Remember red john's foot steps episode ?Please notice to the last part and ask yourself these:
Why there is an officer with Jane and Lisbon when they are talking apparently alone(after arresting Sheriff Hardy)?
Why there is (maybe the same)an officer near Sheriff Hardy's litter?
Why Jane has a shotgun pointed at Sheriff Hardy's body at the same time that he got rid of hand Coffs?
I will answer :
1.Jane hypnotized the officer to be near the Sheriff Hardy's litter with a gun positioned to be very easy to catch by third person (Sheriff Hardy) .
2.Jane needed to kill Sheriff Hardy in his very clever way .Sheriff Hardy's real identity will come to light very soon because of Rosalind Harker's information and as you watched Cho and Rigsby found out .
3.Whole story of joining Jane to CBI is to remove R.J's footsteps .He knew what Sheriff Hardy will try to do(Because he told him so and put hand Coffs key to his pocket) and when exactly it happens , so he got himself ready to act .
And finally notice to the last seconds of Sheriff Hardy when he saw Jane he called him Red John and passed away .
The hole story is about to cleaning R.J foot steps .At season 2 you witnessed that Jane put a microphone under the Basco's table and when Basco called to tell him about R.J's mistakes and new evidences , he already knew about R.J(himself) mistakes .So he hypnotized the secretary and the rest of story happened as he planned .
There is a lot of reasons .Why RJ likes piano ?You may remember that scene Jane's wife and daughter sat at the piano and playing a note(I'm not sure about the music if that music and the music which played when Jane found agent Hicks body are the same ?Please someone check that for me but if that was true where the hell R.J could know about that??!!)
I am curious what happens when the truth come to light and what Jane will do and how CBI solves this situation ?!!!
Just remember the only reason that R.J joined the CBI is to removing his footsteps and make himself impossible to be caught so he can start a new life .
Please share your guess by commenting .

Red John is Patrick Jane. Think of the episode where Luther Wainwright did a psychopathy test on Patrick Jane and according the score Jane was considered a Clinical Psychopath. That was put on the show for a reason and we all know what happened to Wainwright on the last episode of season 4. Also if you remember the episode to where Bret Stiles meant up with Jane and gave him the note that lead to Kristina Fryes location and Patrick Jane asked Bret how he knew about Red John and Bret would not give Jane an answer. This is because Bret has Jane somehow figured out and Jane knows this, but the only thing keeping Bret safe from Red John is his status and willingness to say nothing else about it. I think Jane knows deep inside that he is a psychopath and has multi personality disorder and to convince himself he's not he will stop at nothing to hunt for Red John to later find out its been him all along.

I strongly feel that Patrick Jane is Red John!! Split Personality Disorder and master of hypnotism.

When his wife found out that he was a serial killer apart from being the conman, he killed her and his daughter (or whether they were his real family we don't know!!).
He never wants Christina Frye to be on a case as she is a self confessed Psychic and maybe he feels that if she tries to get closer to Jane through the cases that they work together on then she might be able to find out the secret of his.
All the people who entered in CBI as an accomplice to Red John were hypnotized by him to an extent that they were willing to give their lives for Red John (the lady who killed the cops including Sam Bosco and Craig O'Laughlin).
There are many more theories which could easily confirm that Jane is RJ but we will wait and see.

I seriously wish that I am wrong as that would make my watching Season 4 n 5 more exciting :). Cheerz!!

Patrick Jane is Red John. if im wrong...so be it. I always wanted to write a screenplay where a detective hunts a killer who killed his wife ten years before....and at the end of the story...you find out the detective was a little nuts and was the killer himself. i think its a genius idea....and i think it would be great if the mentalist went that route. it would be absolutely genius if they dragged out red john's identity all the way to the end of the show...and then made the reveal to be jane himself. it would be fantastic

Although highly unlikely, it is possible the Patrick Jane is hunting himself (Red John) with Red John as his alter ego.
I mean, John and Jane has the same personalities when it comes to mentalism.
But they are opposite in reality.

Take the two last names. JANE and JOHN. Male and Female opposites and in the police lingo always used to describe unknown victims. JANE DOE/JOHN DOE. William Blake Poem used Talks of Symmetry.
Jane is the soft side - the Female version
John is the hard side - the Male version
This could explain why Jane can never catch Red John
Also, in the final episode of season 2, Red John recites a William Blake Poem about a Tiger,
Jane orders The Lamb at the beginning. The Lamb is another poem by William Blake.
Lamb and Tiger are opposites.
Jane - Lamb - HARMLESS
John - Tiger - DANGEROUS

And both are taken from the collection: Songs of Innocence and experience. Again two opposites.
Jane - Innocent
John - Experienced.

I'm pretty sure that Patrick jane IS Red john himself.... Think about it , who else can manipulate people into doing things ? and why is he insisting on keeping the red john case to himself?.. If you notice in the episode when jane saves lisbon's life , we can see a cup of tee in front of the monitor where red john was sitting and watching..Is it a coincedence that patrick jane always drinks tee in every episode?..

My suspicion that Patrick is Red John did increase when I watched the first season finale. After all Patrick does not need to do the killings himself, he can easily hypnotized another to do them, with just a touch. However I think is a case of a split personality similar to that of Fight Club.