I think the secret tattoo organization could be some kind of offshoot of the followers of Mitch Laurence. That would explain how Allison got involved after the prison break, which happened months after Victor's "murder". Mitch had many unidentified minions on the outside who could have been organizing their own group while he was in Statesville. I think they might have helped with the prison break, and could also be behind the first shooting of Victor behind Rodi's as well as the attempted shooting of Blair.
I still don't understand how Victor came back from the dead. Maybe there's a secret about reviving the dead on that microchip or that disc that he had. The tattoo group could have had a mole in Irene's organization. Maybe some of Irene's prisoners or workers joined the tattoo people after her operation was shut down.
The other thing I don't get is that if Todd was the one who shot Victor, why did this tattoo group intervene after the fact? Why were they holding and torturing him all that time? This would make much more sense to me if it wasn't Todd, but someone from the tattoo group, who had shot Victor. I thought Todd was imagining the whole thing due to Irene's continued guilt trip on him from beyond the grave. I guess it was just the easiest way to get Todd directly involved, even though it makes no sense. ~)