For me, there are only 2 possibilities:

1- Partridge isn't dead, he is Red John and it was just a trick to caught Teresa easily.
2- Partridge is dead and my number two, Gale Bertram is Red John. If i remember correct, Teresa called him in one Episode as " a clown". This could be the explanation why the Killer painted a Clown-Smiley on her face.

Furthermore:  in my opinion, the List of final 7 suspects is correct. It has to be...