Personally, I don't think it is anyone on the list. The clue I think in episode one at the end wasn't what anyone did but rather the location/setting of what took place.  Watch http://www.youtube.com/watch?v=p43ysF_NFI8 Patrick and Minelli talk about a murder victim who was in an "abandoned house" (just like where Partridge was killed) Red John could have been trying to jog Patrick's brain about that particular conversation in season 6. The voices of Minelli and Bosco sound like they could be Red John with a tad bit of inflection on their part. Comparing body type and hair to the Red John Promo vid for the next episode I'd say it's more like Minelli. Also, Minelli was there from the beginning.  The pigeons....well, could mean "message" as in messenger pigeon.  This was the message Minelli was trying to send to Patrick.