It's not Micheal Kirkland guys....It's Bob!
Here's why
Heller as a personality going by his interviews wants to be the brilliant one here, for that he needs to deceive us and not let us say...Hey we saw that coming or Hey! that was impossible man!
If he brings back Partridge from the dead, fans will say it was trying too hard for a twist and most would have guessed.
If it is one of the remaining 5 it is too obvious.
What is a way of having a brilliant twist without doing any spooky or impossible stuff?
Get the twin angle in. Make us believe that it is Micheal Kirkland who is or involved with Red John, kill bob so all fingers will point at Micheal.
Now if Micheal was the one that was killed by Reede Smith and Bob is still alive, then it would not be spooky like coming back from the dead, because the twin angle is logical and we would still be thinking about Micheal so it would not be obvious.
Bob Kirkland meets all descriptions, all teases from the show producers apart from one, that is when they said 'Red John was there from the beginning' which is a very loose ended statement.
Might be wrong but finally thought of something so sharing. What do you think?
Love your theories!