. >> inside san antonio's bexar county jail, two gangs, the mexican mafia and the tango orejones, posehe 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. 48 inmates but 10 whites in there. it's counterproductive for white groups to cause any tension when they're severely outnumbered. >> the few aryan brotherhood members that i did get to know in the bexar county jail did have a lot of bravado. they were minorities but

during our shoot at san antonio's bexar county jail, we did meet some inmates willing to talk.hey were in a special protective custody unit for gang members who had had enough. >> the ex-gang unit was night and day different than any of the active units we had been to. the inmates had a sense of relief that getting out of the gang provided them, and it showed. >> the ex-gang unit is the only place where those affiliated with warring gangs live together peacefully. but they're fully aware their decisions to leave their gangs carry consequences that could follow them forever. >> we always tell any ex-member of any major prison gang, your life is in danger. there is somebody out to get you. it is going to happen. just remember that you were part of a criminal enterprise and you left it, and there is by their bylaws a hit on you. >> that's the way it goes. you're in it for life or you're dead, you know, there's no -- there's no way out of it. >> victor, who requested we only use his first name for security reasons, once a lieutenant in the mexican mafia. he defected, while serving

. >> such was the case with desiree stalbird, an inmate we met at san antonio bexar county, texas jailr to a variety of crimes. and frequent stays. >> my meth addiction is what got my kids taken away. i love the feel of making dope. i love selling drugs. it's like -- when i cook a batch, make a batch of dope, to me, it gives me -- like when a person has a baby for the first time, the feeling's like, wow. i created that. i miss it. i miss the smell. but i also miss the smell of my kids. i have twin boys. they were taken when they were 4 months old. i used to sit on the corner with binoculars and watch them play in the front yard. because i [ bleep ] up. >> shortly after the interview, stalbird regained her composure, picked up her pass and made her way to the jail chapel for the baptism, an event that just a short time before -- >> hopefully get dunked in the water, have a wet t-shirt contest, praise jesus. >> -- she had seen as merely a way to break up the boredom of jail life. >> desiree stalbird, awesome, desiree. >> looking at desiree, we could actually see that she was engaged and