as a group of inmates at kentucky state penitentiary explain to us. >> i fear none of these guys out here. >> more than one i fear the worse is my clique. it's not a clique, my friends i hang with, these 10, 15 people. i probably fear them the most. i know who they are. the rest of these guys, i don't fear none of them. i hope they watch this, so they all know, the ones that don't can all know. they probably do anyway. >> the only thing i fear is them. >> just because i don't fear them doesn't mean they can't take me out of them, though, you don't have to fear a man to get killed or hurt by them. if he fears you, that's when you have to worry. >> in here, especially, he'll sneak up on you with a knife, a rock, a choke. whatever they want to do, they will get you because they fear you. >> to me a coward will hurt you. he's more dangerous than a stone-cold killer is because he's scared. he put hisself in a situation where he's in a corner. >> that's his only way out. >> yeah. >> and no group of inmates feels more cornered than sex offenders. rapists and child molesters are the pariahs

." >> at kentucky state penitentiary, some inmates can apprentice in an auto body shop. at rikers island jail, a bakery churns out nearly 90,000 loaves of bread per week while teaching inmates how to bake. in many of the prisons profiled on "lockup," inmates have opportunities to learn skills that can help them find work on the outside. but all too many spend their time honing skills more suitable to mayhem and murder. >> i stabbed an inmate 12 times. over some dope in front of the chow hall. >> i took a knife and i stabbed him with it three or four times, until he was dead. then i butchered him with it. >> you find a piece of metal or something, file it down on the concrete. it ain't got to be sharp. just has to have a point. put your hand on it, do what you need to do. >> "lockup" crews are regularly exposed to the tools of a deadly trade. >> in every prison we film in, there's always a shank museum, a place where the authorities display all the weapons that are confiscated by staff. ♪ homemade weapons the inmates have made from bed springs or melted down plastic. i me

." >> at kentucky state penitentiary, some inmates can apprentice in an auto body shop.rikers island jail, a bakery churns out nearly 90,000 loaves of bread per week while teaching inmates how to bake.