There will be more revealed since we have Promo images from "Fire and Brimstone" where PJ has the three suspects with tattoo separated to a wall prior to the bombing and he looks surprised over his shoulder. Something happened by the other suspects and the scene was shot: http://www.razorfine.com/wp-content/uploads/2013/11/the-mentalist-fire-and-brimstone.jpg let's wait and see.