when we met him 15 years later at california state prison corcoran, he was still in prison. and two of his former cell mates were six feet under. glen murdered the first one while he was still in county jail. >> i slashed his throat repeatedly. blood was everywhere. and then another inmate passed me a shank. probably about that long. with a handle on it. i just started stabbing him. stabbed him over 100 times in the back, sides, the neck. he was crying, telling me to stop, begging for me to stop. he was still alive through all of it. i liked that. that was one of my favorite ones right there. >> he surprised me in that he had a gleefulness about him as he was discussing the violence he had committed in prison. he had this proud little smile as he was telling us these very disturbing and violent acts. >> after murdering his cell mate in jail, glen came to prison where his predatory behavior escalated. >> while i was there for about a year i got about 14 assault on inmates. >> why? >> i was a young kid, 20 years old. >> just beating people up, right? >> beating people up for t

. >> among the nation's toughest, california state prison corcoran. severely overcrowded and riffe with racial tension. officers try to maintain order in an institution with a violent past. this is lockup corcoran extended stay. >> most of these people out on this yard could die right there and i would watch them die. i don't care about them. >> when it comes down to it, you miss one beat, you're going to miss the whole burrito. >> from old school prison gangs, to destructive street gangs, it's a dangerous mix. >> bulldogs are at war with everybody. >> officers who have known gang members into the shu where they have a choice, stay in the gang or drop out. >> you're going to have to die sometime. i might as well go out with a bang. >> california state prison corcoran has the largest housing unit or shu in the state. split between two units, the shu houses some of the worst inmates in california. the majority of these are validated gang members or inmates too violent to be housed in the general population. shu inmates are kept in 8x12 foot cells and re

>> this is california state prison, corcoran. a maximum security prison that has housed some of the nation's most infamous criminals including charles manson and the founder of the mexican mafia. despite its reputation, violence doesn't come naturally to everyone at corcoran. >> i don't see myself as being like many of the people here. what i saw the longer i was here is there really is a thin line between them and me. >> before he was an inmate, stefan parro was a librarian. >> i'm here basically because i'm an alcoholic and i've done a lot of drugs, too. drugs are part of my story. >> parro's drug use resulted in a six-year sentence for crimes including burglary. >> at that time i had been married not very long. my wife was pregnant. the fact i couldn't stop drinking and i couldn't stop using, it was difficult to deal with the shame and guilt of all that. >> parro and his wife eventually separated, but he landed in prison for breaking into her home and stealing her credit cards to pay for drugs. >> i readily admitted to it. that

. >> reporter: among the nation's toughest, california state prison, corcoran, overcrowded and plagued by racial tension. we spent months inside with officers trying to maintain order with an institution with a notoriously violent past. this is "lockup, corcoran, extended stay." inmates have been dreaming up ways to smuggle in contraband since 1988. >> there is drugs in prison, obviously. >> whether in the form of drugs. >> it's usually like this. >> or weapons. >> looks like it's made of aluminum. >> piece of stainless steel here. >> off a food court. >> always a race against time for the officer to find the contraband. >> look at that. before it's too late. during the months our crew spent inside corcoran we witnessed our fair share of searches. today on a yard maximum security facility we caught up with an officer beginning his shift with one of three standard cell searches. looking for contraband, stuff they're not supposed to have. not too many apples -- razors, they break them apart. an awful lot in the cell. good weapon. piece a metal. just sharpen that. can't tell what it came

>>> corcoran's a maximum security prison in the california state penal system. we house approximately 5,600 felons. >> this population includes infamous criminals like juan corona, sirhan sirhan, and charles manson. built to hold the most violent offenders in the state, corcoran has seen its fair share of brutality. today a fresh group of inmates arrives at receiving and release, no doubt aware of this prison's reputation. >> when i get on the bus, call their names out to come off the bus, and they're teary-eyed coming to corcoran. it's a shock to them. i guess they have heard a lot about corcoran. >> what do you know about corcoran? >> what i know? i know it ain't no joke. that's what i know. i know this is serious business. >> corcoran is a pretty rough prison here. it's one of the rougher prisons. >> this is how serious it is. it's a life or death situation. it is like that. i don't care what they tell you. it is like that. okay? it is hardcore like that. >> corcoran's general population inmates are split into three main yards. the level one yard consists main

>> among the nation's toughest, california state prison corcoran, severely overcrowded and plagued by racial tension. we spent months inside, where officers try to maintain order in an institution with a notoriously violent past. this is "lockup: corcoran extended stay." >> get on the ground! on the ground! hold him on the ground. on the ground! >> in corcoran, survival is the number one priority for inmates and officers alike. >> you have to live with it. this is what i want to do. so, i'm here. >> whether it's inmates adhering to racial politics. >> i will probably set off a race riot, if i sat right here. >> or officers keeping themselves and the population safe. >> this is what we're looking for. we're always looking for weapons. any time we look for weapons from a cell, that means one less weapon out there on the yard. one less weapon that could be used against staff. >> when these two sides are fighting to survive -- >> i don't care because he wears green. he bleeds just like i bleed. >> the results can be explosive. >> what? >>> in the four months we spent inside corcoran, our

. >> among the nation's toughest, california state prison, corcoran. severely overcrowded and plagued by racial tension. we spent months inside where officers try to maintain order in an institution with a notoriously violent past. this is "lockup: corcoran -- extended stay." inmate interaction in prison is volatile at best. >> dude told me he was going to stab me. i told him to get his knife and i went in and got my knife. >> whether it's with officers. >> you are the captain, man. something has happened to you. >> disputes with other races or gangs. >> i got in a fight on the level one yard. i had lied to home boys, prison home boys of mine and i guess i had it coming. >> or even a prison romance. >> i had sex with my cellie. >> in corcoran it's not a question of if there will be violence, but when. >> everybody down! get down! >> violence flares in the gym on "a" yard and officers move quickly to reclaim control. david salazar, the victim of the battery, refuses to identify his attacker, and the corcoran officers launch a massive investigation. >> l

. ♪ >>> when we met brian at >>> when we met brian at california state prison corcoran, we had a prettyood hunch that the origin of his nickname would play a major part in his story. >> my nickname is lefty. never been called lefty, it's because i have one arm. at 18 i was the victim of a drunk driving accident when i was in the air force. >> the other thing that was significant about brian to me was he was the height of irony on a lot of levels. he was a good example as to why you don't want to take justice into your own hands. his crime was that of a vigilante. >> you know being a christian means you don't have to be scared of your past because your sins, no matter how ugly they are, and we have some ugly ones in this room -- >> he is an inmate preacher at the prison's chapel and can trace the ugliest of his sins to a bizarre series of events that began with the loss of his arm. >> after the air force medically retired me, i retired to little rock, arkansas, started selling clothes in the mall. all i thought about all day long was having one arm, being in the big city where i didn't k

. >> in the exercise yard at california state prison corcoran, we met an inmate whose art is inspiredtell me your name. spell your last name for me. >> my name is kevin moore, m-o-o-r-e. >> what were you convicted for? >> i'm doing a parole violation for sales of marijuana. >> the yard is an interesting place because you never know who you're going to run into, you never know who you're going to talk to, you never know the personality, who they are. i kind of just started looking around and tried to find interesting-looking faces. i happened upon kevin moore. he started telling me that he's a rap artist. he is a ghost writer. >> i have a record deal waiting on me. death row records. for anybody, any rap fans that's listening, my akassassoon. and i got a demo coming out in a few months. if you're a rap fan, listen to it. >> when you start talking to inmates you are not sure what to believe. they start telling you these stories. you're kind of like say, all right. >> i have been a ghost writer in the rap industry for about 13 years. a lot of stuff i have written from behind these walls

when we met christian knight, he was serving 79 years for murder at california state prison corcoran. >> just seeing christian the first time, you kind of knew he had some kind of story. very dramatic looking. you know, with all the tats and very intense. >> it turns out knight had several incredible stories but one involved his attempt to attack a sex offender at the los angeles county jail. >> got this freaking child molester on the tier. he's actually in the van talking about what he does. you know, i like to keep myself, hey, i don't lose my temper. keep myself calm, cool, and collective. that dude made me snap. i get in the van and i tell him, i'm going to rip the toilet off the wall. i'm going to bust through this frickin' glass. i'm going to drag it down the tier, and i'm going to bust through your glass and cut you up your [ muted ]. you're a dead man. yeah, yeah, yeah. then all you hear is steel bending. i got behind the toilet, pushed the toilet all the way back. long story short, i ripped the whole toilet off, wrapped my hands up with my socks, smashed through the glass. he

. >>> california state prison corcoran has one of the largest populations of many dangerous inmates ont coast. our crews have visited here several times and correctional staff is always blunt about the danger. >> when talking to the cos at corcoran, they told me, you come in here, you have to join a gang for protection. immediately. >> when you come to the prison, you have to join a gang. you have no choice. it's a must. >> the prison cannot protect you from the other inmates. it's an incredible admission. >> so you have to have that backup from your other races that are out here, whatever race backs you up, you need to be in their gang because you have no protection. you're on your own and anything could happen to you. >> correctional officers know anything can happen to them as well. >> i'm very well aware that the gangs can reach outside these walls. it may hold them in, but it doesn't hold in their power, the things they can do. i keep my family business to myself. i don't go to areas in the public where i know gangs are known to hang out. i avoid those locations. >> the dangerous

. >> we found an even more unlikely bond at california state prison corcoran. >> like anything.ove and respect. it will treat you with love and respect back. >> we were out on the yard shooting. i looked over and saw these guys petting something. at first i thought it was a kitten. and it ended up it was a gopher that they had tamed. >> we shampoo him. give him little baths. let him run around the cell, feed him apples. lettuce. take care of them. they're good little pets. >> like the best little companion i ever had. >> a lot of the guys we ran into probably have never had anybody to love or anything or anybody to love them. and when you run into somebody who has, you know, adopted a gopher and it gives them some sort of outlet for affection. it's got to be a good thing. >> but we found a very different case of inmate creature bonding inside california's san quentin prison. >> i'm mike miller my real name. and the staff here call me birdman of san quentin. >> the first day i got here at san quentin. the birds seemed to have flocked to me for some reason. and i don't know they p

>> among the nation's toughest, california's state prison, corcoran, severely overcrowded and plagued by racial tension. we spend months inside, where officers try to maintain order in an institution with a notoriously violent past. this is "lockup: corcoran, extended stay." >>> for me, it was a hard, bumpy road. >> bad decisions have landed thousands of inmates in corcoran. >> that is the life i picked for myself, and it's really hard. >> in prison they've got two choices, do their time and go home -- >> i've got a baby brother who doesn't have anybody out there right now. if i go home and he can look up to that -- >> reporter: -- or become even more destructive on the inside. >> more crazy people in your cell, and crazy things happen. >> stabbings, killings, drugs, weapons. >> the path they choose could determine the difference between life and death. >> you take care of yourself, and the rest will fall into place. >> another alarm. >> i live on corcoran, 3c facility. it's a sensitive needs yard for inmates that cannot program around the general population inmates. people with sex c

. >> in an isolated part of california's central valley is corcoran state prison, one of the state'siolent criminals. now, corcoran first opened in 1988 and was the site of so-called gladiator fights in the mid-1990s in which inmates fought to the death in concrete yards while guards allegedly looked on. the guards were charged and acquitted of subjecting prisoners to cruel and unusual punishment. but when we first brought our cameras into corcoran in 2000, the prison was still recovering from that scandal. in this hour, we'll take you back into the highly charged facility to see whether it has overcome its notorious past. >> home again. ♪ >> my life's in danger. if i stay in there, then i end up getting stabbed. >> that's stored under extreme pressure. it's a powder keg. it's a powder keg. >> basically, it's pure hell. it's hell up in here. it's hectic. >> there's nothing here. ain't no roses growing up out of here. >> bottom line, it's punishment. there's nothing rehabilitative about this. >> you lose your freedom, man, you lose everything. >> this is not the place to be. it's not