Funny little realization I just had:

A SMILEY painted in the victim's blood, at the most obvious place in a crime scene, a signature of an "artist with a strong sense of theatre"

I have read some people theorizing it was connected to clowns - carnival - Jane's past, but I think it's just what it is: a smiley in blood.

What does a smiley in blood mean? A comical approach to death. Rejoicing in gore. Having a "love for the macabre".

I think there has been a change of mind on the Red John identity between conception of the character and his apparent reveal. Seems pretty simple and straightforward when you think about it. But then again, I ghould be wrong.