. >> in 1992, robert glen was sentenced to three years for auto theft. 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

it wasn't until 2000 that robert glen koe became the first inmate to be put to death at tennessee inwhat is it like when an inmate faces his final days? it begins and ends with a process known as death watch. >> i've been on tennessee's death row 23 1/2 years. >> the execution chamber looms within walking distance from the inmates' block. it's also known as death watch. >> riverbend has the only execution chamber in tennessee to carry out executions. it was constructed with a death penalty in mind. >> i've had five execution dates. i went to death watch three times and i received a stay of execution. >> death watch is the area where the condemned inmate is housed three days prior to his execution. >> it was really hectic. because, number one, they come and get you, shock you. they take all your belongings, inventory and give you a receipt for everything that you have. and they put it away for family members to pick up. >> i've had several execution dates. i came close to execution i think in the year of 2002. i was actually up on death watch. >> he has been on death row for 18 years

a robert glen is no exception.hough ironically, his prison history all began with one nonviolent crime. >> i came to prison for grand theft auto, i got sentenced to three years. >> but instead of simply doing his time and going home, robert has assaulted more than a dozen inmates, lengthening his original sentence. >> because of all of them assaults, my points again rose to a level four inmate. and the classification committee decided to give me a indeterminant cshu term, and put me up with a aryan brotherhood member, and that began my life as a prison gang. >> the aryan brotherhood used robert to carry out their dirty work. >> prison gangs involved everything from stabbings, killings, drugs, weapons, whatever needed to be done. i did it. >> we warn you. the details of his violent acts is extremely graphic. >> there was an inmate that came up here. he was accused of raping a woman out on the street. because i was up in coming in a gang at that time, it felt to me to either make another inmate kill him or i myself k