>> inside san antonio's bexar county jail, two gangs, the mexican mafia and the tango orejones, pose the greatest throat security. but according to gang investigator officer rodriguez, there are only two pieces in a complicated puzzle. >> in the bexar county jail, there are approximately nine prison gangs, but uncountable number of street gangs. street gangs pop up, literally overnight sometimes. and dissolve as quick lip however, prison gangs have a lot more of a thicker history, it's a larger population, they're actually nationwide. >> one of the larger gang is the aryan brotherhood. >> aryan brotherhood is a true prison gang like the mexican mafia. they have a constitution, a hierarchy, a paramilitary structure. >> at hispanic bexar county jail, the gang is characteristically quiet. >> the white population is very low.