Who is Red John? Keyword being 'who', perhaps it is a 'they' think about how easy it would be. If Red John was more of a company or group rather then person. Think about it, (I'm not good with names) But Jane shot a guy at the end of season 3, the man revealed what Jane's daughter smelled like, but it was later proven he wasn't Red John.. I think in season 2 the man on fire if i remember correctly, tells Jane the same poem 'Red John' Told him. It would seem that Red John is an organization of 20-30 serial killers. All the killings would make it very hard to think ONE man or woman did them.