Ok even if I dont like it My Theory is that its Patrick Jane. It was especially when his daughter in à hallucination asked him if anyone knows who he is. I think that Patrick may have split personalities and La Roche was on his tracks Being an psycologist.
I also red this interview with the creator, warning spoilers....http://screenrant.com/the-mentalist-season-5-spoilers-aco-172407/
And it got me thinking that its Jane. I really hope that its Brett Patridge or Walter Mashburn or his Dad or an evil twin brother but that wouldnt make sense beacuse the creator wants us to experience something special in this show!
Since I think that Patrick has split personalities I dont think he is aware of that he is Red John and therefore he continues his hunt. That is My Theory for now