I find it interesting how Red John has reached every branch of LE. Its not possible until he himself is from Law Enforcement. Of all known characters from the series Minelli is the only one man powerful enough to have reach in all the branches. Second thing is how Red John has not crossed the state borders making California is safe zone as in Jurisdiction of CBI.  

 
       I believe red john  is Virgil  Minelli for a couple of reasons.

            First, when Virgil  gives Patrick Laroche's suspect  list(or so he claims ),

               of Red John's connection, he says it was through mysterious  and underground methods.   Secondly,  as Virgil talks on the phone  with FBI director Alexa Schultz,  she mentions how good it is to have a friend in the FBI,

                                                    the same statement that  Red John mentions to Jane from the backseat of the limo.   I think Virgil is the man.

The hug he gave Lisbon when he retired was one of dread. I think when the mentalist finally stops airing,Lisbon will be his last victim before Jane kills Red John (minelli). 

In S5E5 (when Patrick Jane first meets the CBI team and joins them), Virgil is insistent on allowing Jane to follow Lisben around. Red John wants Jane on the Red John case, so he is using Virgil (or is Virgil) to make sure that Jane (who has no police experience) has an opportunity to take part in the Red John case. The reasons Virgil gives for allowing Jane to follow Lisben around are pretty hollow. During the end of the episode, he also agrees (almost too willingly) to provide the FBI with information about Jane. If Virgil is Red John, he uses his position in the CBI to watch Jane, while also providing information about Jane to the FBI, where he can gain favours from them for helping them. The ending shows that Virgil (along with the lady from the FBI) is a part of this somehow.

"He is mar" not he is ma, or he is man. He is mar most likely means he is Maro. So you ask who the hell in the show is named Maro? Nobody, but one man was, Virgil Maro who led Dante through the hell. Patrick was originally named Daniel, name resembles to Dante, and William Blake was the one responsible for the artwork named Virgil and Dante at the gates of hell, he also wrote The Tyger which we all know. Creators like to play with clues, and they wont give away anything merely important cause it would be spoiled and probbably boring. But if you do some research and tap into the mind of creator, it makes sense.

In my opinion Virgil Minelli is red John. I've rewatched most of the scenes with him in and the looks he gives Jane and the subtle hints he drops. He also has short hair, around or under 6ft, the only doubt I have is his voice unless he uses a voice modifier. He also employed Jane.

I have a feeling rosalind harker is more involved than she lets on also.

Look the Episode S05 Red Down, look at 6.04 ... What do u see?? Yess a ring, looks that the same that RJ have, in the episode when talks to Rosalind, dont u think? :S

OMG I love this show :D :D..!!