Firstly is obvious that Red John is a powerfull and well connected man. We can see this because he can afford a limo and also several resources, such as software to spy on CBI and to hack there network. Besides when RJ kills his copycats we can see his wearing a suit and good shoes(killing the copycats wasnt a planed kill so he must likely went to kill them with what he was wearing in his normal life). So i will assume that he is rich, I will consider him a well sucefull business man. He is also very persuasive, and bored with his life, needs excitement (if u check mashburn's episodes you can see that he fits the profile, and for some reason in one of his episodes a lot of ppl are wearing red clothes). On the first season it was wrote on the wall "he is Ma", which could be " he is Mashburn". And Finally We know that patrick Jane meet RJ already.
This is my opinion, sry for some grammatical errors