SECOND SUSPECT - Brett Partridge

Reason 1. He's always on The Red John cases.

Reason 2. He hates Patrick and Patrick hates him. 

Reason 3. He is a strange man.

Reason 4. He fits the description of Red John and the voice.

Reason 5. There is a painting by William Blake which is called A Brace of Partridge. He recites a poem "Tyger Tyger" by William Blake.

Other things.

1. As anyone noticed that when Danny and Jane visited the grave stones it was just there names, no date of birth nor death....strange...Grave stones usaully have this. By the way I'm the same person who had Danny as top suspect