My evidence is this:

Anagram:

TygerTygerThomasMcAllister

I am the scraggly ratty molester

McAllister in the wedding episode pretended to be afraid of heights to play with Jane. Only RJ would know that info and that Jane would be looking for that.

McAllister was two steps ahead of Jane in the end, he was there waiting for Jane and his captor. Only Red John has demonstrated the ability to anticipate Janes' moves and their results before Jane does.

Its him.