noestra familia is known as nf, family. >> the northern structure is composed of california hispanicsm north of los angeles. >> nazi low riders. they refer to themselves as the nlr. >> the nazi low riders is a white supremacist gang formed in the '60s. membership can only be achieved by killing someone, and death is the only way out. >> the bgf is the black gorilla family. >> the black gorilla family is the only recognized black prison gang. street gangs like the crips and bloods are merely regarded by prison officials as disruptive groups. but the most notorious gang in the california prison system is called the mexican mafia. >> the mexican mafia is known as m.a. they'll be recognized by eme, which is the spanish letter "m." >> the mexican mafia was born in california prisons in the mid 1950s. its members, who swear allegiance for life, are mostly mexican-americans from southern california. among gangs, the mexican mafia is considered the most disciplined and powerful within the california prison system. >> if you're an active gang memberer you're expected to be up at 6:00 in the mo