Just something interesting to further back up the notion that the final word about Red John is not spoken yet:

Official twitter of Reed Diamond:

https://twitter.com/reeddiamond/status/439264991590350848

@reeddiamond Did you ever think you'd be Red John or did you think it was someone else?

“@kentjohnson26: @reeddiamond Did you ever think you'd be Red John or did you think it was someone else?”
How do you know I'm not?"