The tattoo is not actually a tattoo its a scar. a scar from a tiger, and the secret organisation know this hence 'Tyger Tyger' and Jane was a carnie/circus man, and circuses have tigers. Anyone who knows about the 'Tyger Tyger' is a member of undercover agent from the 'secret' organisation
I huv reasons to say RJ and PJ is one person although Bruno Heller always
says isn't he ?1-I think Jane after death of his wife and daughter developed some sort of mental disease what we called shizophrenia. Huv two separate personalities kind one and violent one2-he hallucinated about his dead daughter its auditory hallucinations its positive symptomplus visual hallucinations 3- the episode when agent darsi said to him an important question if ur an enemy of red john why he didnt kill you4-when agent darsi re opend old case panzer murder no body knows that except Wainwright so how red John know and send someone to follow her