and he goes, they do. >> what if someone asked you to risk your life? >> what if i shape get changed? what if i get killed? >> to go undercover. and one of the country's most dangerous presents. >> once they stepped out the door, i was on my own. >> they helped him catch a killer. >> she had such a zest for life. >> young girls were being murdered. >> i can't imagine sending my daughter off to school, and never seeing her again. >> and investigators needed health to get a confession. >> if anyone could pull it off, he would be the problem to pull it off. >> but this was different, he was always be a convicted felon. if it worked, he could win his freedom, if it did, it he could lose his life. >> they had your back? >> they had my back. >> that's what you thought? >> that's what i thought. ♪ ♪ ♪ >> hello. and welcome to dateline. jimmy kaine was a smooth talking convict serving a ten year sentence. when he was offered a deal. if he helped prosecutors pry a confession from a suspected serial killer, including a location of the victims body. he could walk away a free man. and it was dangerous undercover work requiring him to spend life behind bars of a federal fifth is present of the criminally insane. getting and was easy, getting out alive would be much harder. here is lester holt with the inside man! >> two enemies, who did not trust each other faced off across the table. one of them in handcuffs was a clever con named jimmy keen. the other? a hard charging prosecutor. >> -- >> the prisoner was worried sick. larry beaumont's, the prosecutor who had just convicted keen and put him behind bars. suddenly wanted to talk. a top secret meeting, no less. what more could he do to jimmy? >> it was the last person i expected to hear from. it was my biggest fear. >> but keith fears went off the chart, when the prosecutor slip an accordion file in his direction. on top was a grisly photo of a dead girl. >> i flip to the next page, and here is another dead girl. i'm thinking, whoa, wait a second. >> he's thinking at this point you're about to charge him with something else? >> yes. because i had been pretty rough on him in the initial prosecution. >> jimmy was in the dark. he had no idea of the crazy scheme that beaumont had in mind. >> he says jimmy, he says listen. this is something that we had another person on. he has killed many, many young women. and i personally think that you are the one that can help us with this. >> this, turned out to be an investigation into trying to catch a suspected serial killer. beaumont, an outside the box thinker, believe that this conflict, jimmy key, was the one who could somehow crack the case. taking on a unique, and deadly mission. >> i realized how serious it was, and i also realize the danger of it. >> but what he could not know was how such a daring mission would change his world. and the person that he was forever. if this all seems fodder for a hollywood movie, brad pitt would agree. the megastar who was benjamin button, and money balls big d b, considered playing none other than jimmy kaine. >> brad pitt likes the fact that this guy, jimmy keen, risked his life to try to find what he could find. >> clearly, this guy is one of a kind. charismatic, conceded, courageous, and complicated. from an early age, he had the personality, charm, and cockiness that made a dream that are hollywood star would one day one to play him in the movies. his first big brush with fame came on the football field. >> i heard that they called you the assassin in football? that was a good thing i take it. >> yes, i was taught by my dad at a young age. he says son, he goes, if you don't hit that guy first, he's gonna hit you and hurt you first. >> a superstar athlete, and mr. popularity in high school. he seemed to have it all as a big fish in the river city in illinois. a blue collar town south of chicago. >> i had was the most valuable player, i was the captain every year that i played. >> he grew up in the shadow of his father, big jim, a giant of a man who was a cop, firefighter, and hero to his son. >> he was my best friend. he was on my back on everything i did. >> but all this potential would be put into peril by a terrible choice that he made. as a teenager, he began to sell drugs. he started small. peddling bags of marijuana, here in this park. then he expanded to cocaine, and at the tender age of 17, he moved to chicago where the business, and profits exploded. he was now a big fish in a bigger pond. lake michigan, to be exact. he was his own in crowd. fast cars, and souped up living. >> all the hotspots, all the big nightclubs. all the owners i was tight with. i would have lunch at every place i went to. >> where you -- >> yes there was a certain point where it wasn't invincible feeling. >> did your father? now he's suspect? >> he didn't suspect until much, much later. >> it would be a rude awakening for both his dad, and jimmy that day in 1996 when jimmy was just relaxing and one of his chicago homes. >> and all of a sudden, come boom, the whole door is blew off. the hinges come flying into the house. and all this da, fbi, and locals came in in fine gold line and weapons pointed. telling me to get on the ground. >> he -- spearheaded by the hard-nosed federal prosecutor, larry beaumont. >> we scooped him up in an operation that iran. we called it operation snowplow. >> and in court, beaumont showed keen no mercy. >> he was coming at you on all fours? >> oh yeah. he's a bulldog. >> jimmy was convicted, and slapped with a ten year sentence. >> it was a ten year sentence, and i knew he did not expect to get ten years in that case. >> your farther was in the courtroom? >> i knew i let him down in probably one of the biggest ways you can let someone down. >> his future was bleak, he faced ten years away from his glamorous life. the fancy cars, the big bucks. but in 1998, just when all hope seemed loss. his old nemesis, beaumont, came to him with an offer of freedom. attached to that accordion file that he slip across the table. in return, cain would have to agree to risk everything. and become an undercover informant in one of the roughest provisions in the country. the maximum security lockup in springfield, missouri. it was a psychiatric pridgen with both hard-core killers, and the criminally insane. >> these people all have life sentences. they're all in their, and their crazy. and they have nothing better to do than trying to hurt you, and kill, you for some fun. >> if he accepted bull montes offered, his target would be the suspected serial killer. a mysterious man in a van. >> coming up! every picture tells a story. >> when i put the picture down, he flinched. raised his arm up, and refused to look at the picture. >> when dateline continues! sometimes, the lows of bipolar depression feel darkest before dawn. with caplyta, there's a chance to let in the lyte. caplyta is proven to deliver significant relief across bipolar depression. unlike some medicines that only treat bipolar i, caplyta treats both bipolar i and ii depression. and in clinical trials, movement disorders and weight gain were not common. call your doctor about sudden mood changes, behaviors, or suicidal thoughts. antidepressants may increase these risks in young adults. elderly dementia patients have increased risk of death or stroke. report fever, confusion, stiff or uncontrollable muscle movements which may be life threatening or permanent. these aren't all the serious side effects. caplyta can help you let in the lyte. ask your doctor about caplyta. find savings and support at caplyta.com. how long have you been tracking the value of our car? 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[girl squeals with glee] with ring you're always home for the holidays. learn more at ring.com. >> several years before jimmy several years before jimmy keene's arrest and conviction, his drug business was booming. came to arrest and conviction, the drug business was booming. and the personal life, as he tells, it was nonstop fun and games. a lot of hot clubs here in the 90s. >> this was the place that you are doing business as well? >> we want to play right here yes. it was a good time. >> back then, he had no idea about the danger lurking 150 miles south and a lifestyle away that will change his life forever. rural, tranquil georgetown illinois is where carrie roach and her husband were raising their 15 year old daughter jesse and two other children, fire removed from the big city crime. >> everybody knew everybody was, so they were conscious of what was going on usually. you can count on somebody to go after your kids if they need it. >> in 1993, jessie was a high school sophomore devoted son home and family. >> jesse was really very much of a home body, so one of the road and back, she was done, and then she would be watching gone with the wind. >> one money in september, jessie went out for a bike ride but just minutes later, her sister noticed jesse's beloved bike down on its side. in the middle of the road. >> not on the side of the road, in the middle of the road? >> yeah. she would put the kick stand down instead of the bicycle, she would never lay the bicycle down, and immediately went down there and there was a bicycle. and we knew something was wrong. >> gary miller was the deputy sheriff of dispatched to the scene. >> the more that we learned about the family and the girl's background, we just did not feel that she was staying away by choice. >> a hunting image of a bike tripped over and abandon, terrified all the investigators and of course jesse's family. >> you never lose the hope for them not wanting to come and walk, in we knew that she was not just gonna walk away. >> after six weeks, jessie's parents worst fears were realized, her body, beaten and sexually violated was discovered in a cornfield. >> it can never be easy telling apparent that their child is dead? >> no. it was not. but at least we were able to tell them that this is her and she is gone. we were able to erase all doubts. >> gary murder had a murder case dissolve and it was now a federal case involving prosecutor larry beaumont as well since jessie's body had actually been followed across the illinois state line. for the next year, miller did lots of legwork but to no avail. >> every day you get up in your thinking about this case? >> oh yeah. >> what if i? missed >> exactly. >> i know this case really shook him from the beginning and he would check any and all leads with that would involve girls, and run them down. >> then, in late 1994, his persistence paid off. a man in a van had been reported chasing two teenage girls in jessie's hometown of georgetown. miller trace the van to a man named larry hall, from indiana. a three hour drive from georgetown. >> is the heartbeat starting to pick up a little bit? >> yeah. i think this has to be checked out. >> miller learned that hall was a gun war civil war in reenactor. a soldier who traveled the midwest to fight fancy battles. he immediately drove their to interview hall who was not saying much, so miller showed him a photo of jesse roach. >> when i took the picture down, he flinched. raised his arm up and turned in his chair. and refused to look at the picture. >> convinced that larry hall was hiding something, miller became obsessed with making a case against him. days later, back in illinois miller turned up a huge lead. he found witnesses who vividly remember hall from a revolutionary war reenactment in the georgetown area, the very weekend before jessie was abducted. to them holstered out for his birdie she, mutton chop sideburns. but also for playing a soldier who was fighting the wrong war. >> he was rearing a civil war uniform. and he had a civil war hat. >> and a revolutionary war? a reenactor? >> exactly. >> armed with this new information, the deputy sheriff returns to wabash for a second crack at hall. this time, he pressed his suspects far. they're saying that the reenactor's had seen him there georgetown. >> he came along to the point where he said, you know, i do so many reenactments i could've been there. i don't remember. because i go to a lot of them. >> he's giving a lot more ground? >> right. >> so miller see the opening and kept at it. finally, he said, hall came clean and confessed. and he abducted, sexually violated, and strangled jesse rose to death. >> how much did he give you about the killing of jesse roach? >> good detail. what he actually dead. and what took place. >> not only that, he says that larry hall confessed to other killings. including a coed from indiana university and nearby mary and indiana, name trisha wrangler. >> he did say that he was involved. >> deputy shareeduh did not know, much, so he called the indiana police who have been handling the case. but when mary entered active and other indiana cops arrived, hall was suddenly telling a much different story. he denied confessing to any killing. including jesse's and trisha's. what is more, he claimed that it was all a misunderstanding. and about disturbing dreams that he had. >> he takes us out to a location, i struggle here, we left her to lay here. we searched the woods, we searched the area, never found anything. >> the indiana cops familiar with paul were not at all surprised by his actions. some of them like j. k. thought hall might be a want to be. a pretender who gets his kicks by confessing to crimes that he did not commit. >> is it possible that he is simply obsessed with these cases but not involved? >> there is no doubt in my mind, that he does follow these cases. that he does read, and is attracted to two cases. all over the country. so the question does come, is he a want to be? >> deputy sheriff miller, and prosecutor beaumont however, felt certain that they had a real killer on their hands. a serial killer, with a unique mo. he would drive cross country to reopen accidents and play fantasy soldier. then pray on young women, and kill for real. >> the fbi started discovering girls that were in fact missing various areas. at the time that larry hall would've been there. >> but the only case which prosecutors had significant evidence was jessie roach. larry hall was arrested in connection with her death, even though he denied that confession a miller. hall went on trial in 1995. >> as a prosecutor, what is the best card that you are holding? >> well, we had a statement, his confession, said he did it. >> valmont called deputy sheriff miller to the stand. to testify that hall had admitted that he had abducted and killed jesse, when he's spotted her with her bicycle. >> he was walking the bike at the height. >> in the confession, paul gave him a detail that only the killer would know. that jesse was not riding her bike, but walking it. as safety precaution that the roaches insisted that they follow when on the narrow road. >> that was not in the press that she was walking the mic that day? >> yes. >> when you heard that, did he give more credit to the story? >> yes. it sealed it for me. i knew that he was the one. >> a jury, unanimously agreed. it took three hours to convict larry hall. but prosecutor beaumont believe that this was just the tip of the icicle. he felt certain that hall was a serial killer, and he had to find a wave of proof. so he began investigating trisha's abduction. a case that was in his, for a family he did not know. >> i can't imagine sending my daughter to school, and never seeing her again. >> and he came up with an outside the box game to get all. which would risk the life of that charismatic convicts that he had just put away for dealing drugs. jimmy keen. >> what happens when i have to deal with all of these crazy colors and stuff? what if i get shanked? what if i get killed? am i gonna survive this? >> jim is get out of jail free card comes with a heavy price. >> coming up! >> they had your back. >> they had my back. >> that's what you thought? 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[splash] before advil: advil dual action fights pain two ways. advil targets pain at the source, acetaminophen blocks pain signals. advil dual action. lowe's knows black friday savings ace should be moreks than just one day. that's why we're giving you black friday deals every day. where you can find the best value all november long. shop now and save big, in-store or online. >> people typically do not people typically don't admit murder-- admit murders, sexual salts and murders, to police officers unless in facts they have probably done it. but it's clear that they felt that he was responsible for the murder and disappearance. >> she had a zest for life, and she would walk in the room and everybody knew she was there. >> trisha, a 19 year old psych major at indiana university was on her way to becoming a family counselor. >> her goal was to be able to put families back together again. >> then, in march of 1993, donna and gary received the late nine phone call that every family dreads, a cop from indiana was on the line. >> he says that do you know where trisha is? >> in my heart, i knew that something was drastically wrong. >> she had walked to an off campus supermarket and never returned to her dorm. more than 25 years later, her parents are still waiting. >> we have no answers. and somebody out there, that is where somebody is,. >> trisha wasn't the prosecutor of the beaumont case, but he was deeply moved by her parents. >> that's what got to, mate they knew about the facts of the case, and the family, and i had read it, and i read all the newspaper articles. and the accounts of them asking for help. >> beaumont fell certain that suspected serial killer, larry hall, was responsible. not only did hall live 25 minutes from indiana. he had been identified chasing to coeds there just a week after tricia went missing. so in the summer of 1995, a month after convicting hall for jesse roach's murder. they had the search for trisha. it was in those same indiana backwoods where hall had told indiana authorities that he had killed and buried trisha. >> i wanted to feel like i did everything i could to see if we could find her body. >> but after two days, searching in sweltering heat and humidity, the body did not turn up. >> does it mean it wasn't there. >> then, beaumont decided to try something completely different. >> i came up with the idea of putting somebody in the prison cell to see if we could