[Spoilers] Was there a snitch from the beginning?

So we know that Micah was a FUCKING RAT (or a SURVIVOR, BLACK LUNG) and according to Agent Milton this started after the Guarma incident, however the gang’s “bad luck” started way before that (Blackwater Massacre, the law showing really fast at the train robbery during Chapter 2, this was even referenced in the newspaper, the failed robbery of the Saint Dennis bank). So my question is, was there another rat in Dutch’s gang or simply really good police work plus really bad luck? Has anyone found leads to whom he/she may be (OR MAYBE CAIN WAS THE SNITCH)?