It is obviously not partridge cuz he is dead
A suspect told jane that red john had 3 dot tattoo on his left hand
Jane brings all 5 left suspects and figures three of them have the tattoo
Burtram ,smith and Mcallister so I assumed it must be some group
That would explain why did Burtram ask Mcallister and smith "how much does he know" after talking to Jane
So I think that red john is a hole group of
Gale Burtram
Sheriff Mcallister
Reed smith
Are
RED JOHN