If you watch the last scene of ep 6 closely you will notice that Brett stiles does have a tattoo on his left shoulder but it's not 3 dots it's an anarchy tattoo which has similar meaning to the 3 dots tattoo it symbolises anti-government movement it's also used by people who feel they don't belong to any group or cult of certain people however I wonder if it's an actual clue if not then why is it there also I don't believe that red john is the one who killed the pi for two reasons first he is not sloppy to leave her like that he should've sliced her off second his shadow can be seen a moment before he enters and it doesn't look like any of the possible suspects except for maybe Kirkland but I don't buy it one last guess I believe that the wait no that was heard before the gunshot was Bertram's jane asked the three to explain the whole tattoo thing or he will shoot them one by one until one talks so the gunshot was just an attempt to crack one of them so he reveals the tyger tyger conspiracy but can't reveal everything because of the bomb I don't want to seem too meticulous but the explosion started from where haffner and stiles where in the room