Hello everyone - after reading a lot of theories and thinking about who Red John is for a long time - i finally would like to explain my latest thoughts. It's not really the try to finally determine who out of the 7 suspects is Red John - but some thoughts. 

So let's get started, right? 

Most important things first: I think, it COULD be Michael Kirkland. Now before you start yawning and screaming "no - he is dead, dude!" - let me explain. 

When Bob/Robert Kirkland explained his background story to Patrick in Episode S06x05 - what do we learn? 

We learn about his mother, his dad and his brother. 

His dad beat "the crap out of all of them". Until their mother left - with the razor-blade. That's what kicked my theory off. Bob left as well after some time. And when their dad died - michael become the alcoholic. Nothing new until yet. 

But then he met someone. As Bob said "someone who finally could help him". Or as Patrick said "More than that - a savior". 

Bob believes that it was Red John who helped Michael. But I'm not right sure about it. He never met him by himself (we know that because of..well then Bob would know Red John, right? :P ). 

Thinking of the time and the circumstances...couldn't be it that the person who helped Michael wasn't Red John but - Bret Stiles? 

Someone who helped him out of his misery, a "savior"  and someone who only wanted devotion and sacrafice in return. Does sound like the things that powerful cult-leaders are made of, doesn't it? 

So... the next thing: Despite the killing of the Janes , Dr. Towlen Morning and Panzer - we still don't know WHY Red John started killing. We do only know, that mosts of the time, he kills woman (after raping them) and then draws his mark somewhere. 

And why a smiley? A smiley, that also looks like it is crying? A symbol that many, many people would associate with something "childish"?

So let me start with my theory: 

What, if Red John is Michael Kirkland. And as Jack the Ripper was killing prositutes for avenging the doing's of his mother (which he hated) - Red John kills woman. He kills Mothers. His mother wasn't helping him or his brother when their dad beat them. They were probably crying and suffering like hell - but she didn't help. (maybe because she just didn't know how to). 

So Red John aka Michael is killing Woman - just because of his hateress of woman(but that also just an assumption) and paints a crying, childish face on the wall. If Jay Roth has no psychiatric history (no treatmens) - so doesn't Red John probably had some - so he never had help to get over all of that. He is out for blood and revenge.

Her mother killed herself with a razor blade - maybe is that (and the fact of the slow, painful dead) the reason why he uses knifes. 

But how could have Michael shook Patricks Hand? That's the fact I'm not finisehd with yet. Maybe he infiltrated CBI sometimes by playing his role as "Bob"? Not sure about that - but from a psychological point of view it would fit. 

Also - that would know why Bret Stiles knows who Red John is and is a little bit laughing when Patricks says "One of you is Red John"  - as Red John isn't in the room. Bret won't be Red John - he made more than one aspersion about Red John - and a person who's actions base on his ego won't do that. Someone who doesn't like to be slandered would not talk like this about himself. Even not to keep his disclorue up. 

Also what COULD be a fitting fact: He likes Teresa and spares her life. Maybe because he just wanted to send a message to Patrick via the sign on her face - or just not to end the game yet. Who knows. But maybe he likes her, because she suffered as a child as well - like Michael / Red John - she suffered under an alcoholic dad. 

So that's one of my theories. The other ones are "just" from tiger tiger (which i think is a very bad thing in the plot but it's okay). And Haffner..well...he is just acting weird and is a bit foolish about that or just doesn't recognise what his actions are looking like. Who knows. 

Thanks for reading!