♪ this is "nightline." >> the most infamous unsolved serial killing spree in wichita history. >> he is one of america's most notorious serial killers. >> he calls himself the btk strangler and promises to kill again. >> btk stood for bind, torture, kill. that was his m.o. >> as dennis rader service 125 years in prison for 10 murders, his daughter opens up about being raised by a hidden monster who was living in plain sight. kerry rosson telling abc's deborah roberts the moment she found out who her father really was. >> you realize, my god, my father's a psychopath. >> how she provided the missing

key. plus her stunning admission. >> i still love my dad today. >> "nightline" will be right back. wait... do we have to thank our moms twice? i don't know... (laughs) breyers. 100% grade a milk and cream, and loaded with delicious cookie pieces. better starts with breyers. rinsing the dishes before they go in the dishwasher? well, cascade platinum has 50% more cleaning power, so you don't have to. its food-seeking enzymes break down food into particles so small they can flow right down the drain. plus, it's powerful enough for the quick-wash cycle. cascade platinum with 50% more cleaning power! ♪ ♪ ♪ ♪ ♪ ♪ hey google, turn up the heat. ♪ ♪ ♪

receive a chargepoint home flex charger or a public charging credit. see your volvo retailer for details. at usaa, we've been called too exclusive. because we were created for officers. but as we've evolved with the military, we've grown to serve all who've honorably served. no matter their rank, or when they were in. a marine just out of basic, or a petty officer from '73. and even his kids. and their kids. usaa is made for all who've honorably served and their families. are we still exclusive? absolutely. and that's exactly why you should join. "nightline" continues. here now, deborah roberts. >> on february 25th, 2005, when i found out my father was arrested, this place became not

my home. and no one ever slept in my house again. >> he calls himself the btk strangler and promises to kill again. >> btk's brutal crimes shocked wichita. >> the most infamous unsolved serial killing spree in wichita history. >> btk stood for "bind, torture, kill." and that was his m.o. >> reporter: three letters which can touch off memories for anyone who lived in wichita during the 1970s. >> btk emerged in 1974. >> when btk came forward, everybody's life changed. he would see a woman walking, and he would say, she's next. >> reporter: one minute you had a loving father. >> right. >> reporter: the next minute he's a serial killer. i mean, come on. the child of a serial killer actually talking about it? that's something you almost never hear. kerri rawson was 26 years old on the day she learned her father was the cold-blooded killer known as btk, the man

responsible tordf for killing t people and terrorizing wichita, kansas, for years. >> there was a knock on the door, he said he's the fbi. he says, your dad has been arrested as btk. and i was like, i think i'm going to pass out. >> wichita was a wonderful city back in the 1970s. just a nice midwestern city where people could raise their family without any fear. >> never in a million years did wichitans think that a serial kill we're come from here. >> my dad and mom met in the fall of 1970. he had just got back from the air force. started dating, married nine months later in may of '71. >> reporter: while rader appeared to be a happily married man, his monstrous behavior would emerge one winter night. >> this starts january 15th, 1974. the home of joseph otero and his wife. >> he says he spot the mrs.

otero and one of her daughters when he was driving my mom to work, then stalked their family. >> reporter: he went to the house and cut the phone line. then killed both parents, along with their two youngest children. >> when the older children came back from school, they discovered their parents. >> i ran down the hall. went in their bedroom. and saw my mother on the bed, my father on the floor. my heart just got ripped out of my chest. my life changed instantly. >> 11-year-old josephina otero bound with rope, hanging just off the floor. >> leaves his dna at the scene and leaves. >> reporter: police did pick up ple men for the otero murders, which angered rader. >> killers like dennis rader, they're called power control killers. they love the power, they love the control, they want the attention. what's a natural way to get

attention without identifying yourself is to interact, call the media. >> reporter: rader calling the local newspaper, claiming to be btk, during the coursing them to proof. >> this guy tells them to look in the city library, tells them a specific place, goes to the engineering, the shelf, the book to look for. >> the police find the book, and there is a letter that describes the otero murders in detail. in the letter he suggests the moniker "btk," which would stand for "bind, torture, kill." >> reporter: in 1975, rader became a father, by day led the life of a normal family man with a job at a security company. but -- >> from 1974 to 1977, he will kill three more women. a college student named kathryn brig bright. a mother of three named shirley vieian. a 25-year-old named nancy fox. >> he called in the murder of

nancy fox. >> you will find a homicide, nancy fox -- >> the caller said, reporting a homicide, police went to that address and found nancy fox dead, bound and strangled on her bed. >> you will find a homicide -- >> so when you heard this, did it sound like your father? >> you can hear, like, that clipped -- the way my father could talk. >> how would you describe your childhood? >> pretty much the american dream. three-bedroom ranch, big backyard, springer spaniel dog. and then when i was 4, he built a massive treehouse for my brother and i. it was extremely out of the characteristic of my father to be physically abusive. >> reporter: but his murderous intent never went away. >> april 27th. it's 1985.

and maureen hedge, who just happened to be his neighbor, about six doors down, becomes victim number eight. >> the body was nude, and police say badly decomposed. a pair of knotted pantyhose were lying in the ditch beside it. >> over the next five years, he kills two more women. vicki legerly in september 1986. and dolores davis. >> after he murdered dolores davis and went silent for a very long time. >> reporter: after the last killing in 1991, life went on for the rader family. kerri going off to college and meeting her future husband. >> he just seemed like another regular wichita dad, to me. >> and then in 2003, my dad walked me down the aisle at our wedding. >> reporter: in 2004, a local paper writes an article about the 30th anniversary of the first btk killings.

nobody remembered him.there tha- which invoked his ire. >> this morning we have more information on the letter sent to the "waive talk eagle" by the btk killer. >> btk started sending packages with mementos from his crimes. >> reporter: one of those boxes contained a floppy disk. >> we got into the meta data and it showed that it had been typed on by a computer at a church in park city. the name of the computer was registered to the name of dennis. >> reporter: investigators found the church president was dennis rader. they also had an old dna sample from the first 1974 crime scene. >> overnight we called 200 policemen, we had helicopters, we had resources, we had a tank. >> we pull him over, and before he can hardly get it in park, we're yanking him out of the car. we put him down, he looked at

the detective that had handcuffed him and said, "would you let my wife know i won't be home for lunch? i assume you know where i live." i got chills. >> btk is arrested. >> police say 59-year-old dennis rader is the btk strangler. >> you were still at that point convinced they had the wrong man? >> i think reality was starting to creep in. i felt my stomach just twist. realizing it could be true. >> reporter: his confession recorded during police interrogation. >> i guess you got me. what else can i say? >> it took awhile for dennis rader to start talking, but once he did, he told police more than they bargained for. >> the belt that i used was the belt that i was wearing. i had her come back, and i whispered in her ear a little bit, i told her i was btk. i was a bad guy, and she really squirmed. >> he spoke over 30 hours. >> she said, what's going to happen to me?

>> he showed no remorse, no regret. the only regret he showed during this was that there weren't more victims. he told us that we would discover what he'd termed his mother lode. >> there were journals and drawings. he had material that he collected from each of his victims. clothing, car keys. >> he had compartments everywhere. he had false bottoms in the closet, he had stuff in the crawl space, he had stuff in the treehouse he had made for his kids. >> reporter: one minute you had a man in your life who you thought was a loving father. >> right. >> reporter: the next minute he's a serial killer. >> right. i had to learn how to grieve the loss of somebody i loved very much. that no one else loved anymore. up next, how kerri unwittingly played a part in her mother's capture. >> it was -- felt like an invasion of my privacy. >> plus how she found it in her heart to forgive her dad, even after he admitted to the notorious murder spree.

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♪ "nightline" continues. here again, deborah roberts. >> btk is arrested. >> police say this man, 59-year-old dennis rader, is the btk strangler. >> reporter: after 30 years, the btk killer who terrorized the city of wichita, kansas, was finally in custody. >> we have learned that rader has been charged with ten counts now of first-degree murder. >> reporter: the community in shock. dennis rader was a serial killer

in plain sight. >> dennis rader is literally the least likely suspect. he is a pillar of the community. he's the president of his lutheran church congregation. he is a compliance officer. he wore a badge. >> reporter: it was daughter kerri who unwittingly and inadvertently helped officials make the arrest. >> they got a warrant for my medical records at the college health center. >> you had no idea? >> i had no idea. they found i had annual pap smears, they had a sample of my dna. >> in some ways your dna sealed your dad's fate. >> it did, but nobody told me this. it would have been nice if someone had asked me for my dna. i would have willingly given it. it felt like invasion of my privacy. >> he didn't think they had kept biological specimens from the crimes he had committed all these years. then they brought up the dna. and they could nail him. >> isn't any way you can get out

of the dna, right? you can't get out of the dna unless you've had a total blood transfer, it's there. >> reporter: while in custody the story of the btk killer drew international attention. >> everybody wanted to talk to dennis. i wrote him a number of letters. and i'd included my phone number. then on one saturday morning i get a call, the operator says, "will you accept a collect call from the cedric county detention facility?" ied a btk on the phone. >> i have a recorder going if that's all right with you. >> sure. >> can you pinpoint when you knew that there was a problem coming? >> well, i would say probably even when i was in probably grade school i started having problems. >> what kind of problems were those? >> oh, sexual, sexual kind of fan attentions. mine were probably a little weirder than other people. >> he talked about the hunt. >> the hunt for the object. it was more of a high, i guess,

than it was actually them. >> he told me he got a high from it. fnding the woman then ilkilling her. that was what turned him on. >> do you have any remorse over the killings? >> remorse? yes, i do, i do have remorse. i feel sorry for them. >> dennis rader told me that he felt sorry for the victims. well, no one believes that. >> it was more like he was are so sorry that he got captured. >> bottom line, i want the people of cedric county, the united states, the world to know that i am a serial killer. and i'm going to pay for it. life sentence. >> after i hung up the phone, i remember thinking, i've just talked to a man who has no soul. >> reporter: facing overwhelming evidence of his crimes, rader pleaded guilty. >> those plea hearings are usually 10, 12 minutes. this one turned into about an hour and a half. >> reporter: with the courtroom transfixed in horror, rader recounted the agonizing details of every murder.

>> i did mrs. otero. i'd never strangled anyone before, so i really didn't know how much pressure you had to put on a person or how long it would take. mrs. vian, i went and tied her up, bag over her head and strangled her. >> here is this man standing up in court, in what i imagine is his church suit, recounting the murders of his neighbors one by one by one. >> he makes himself sound like he's mr. good guy, you know? i got mr. otero a pillow. like, before i strangled mr. otero. >> i tried to make mr. otero as comfortable as i could. apparently he had a cracked rib from a car accident. so i had him put a pillow down over his head. >> i was kind to him before i killed him? >> that's where that massive disconnect comes in and you realize, my god, my father's a psychopath. >> reporter: later at listen tensing, the killer confronted by his victims' family members.

>> for the last 5,326 days i have wondered what it would be like to confront the walking cesspool that took my mother's precious life. >> reporter: then he was allowed to address the court. >> thanks. i can't believe the people have felt me on this. you have to appreciate the police department. they've done a lot of work. i hope i pronounce these people's last names right. >> all the families walked out. they all got up, turned around, walked out the door. >> he's thanking everybody, like the police. then he basically said, like my family were pawns in his game and social contacts. >> reporter: the judge condemned him to ten life sentences, the harshest punishment at the time. >> do you think your mom had any clue that your dad was doing anything criminal? >> no, mom and i both said, if we had had an inkling that my father had harmed anyone, let alone murdered anyone, let alone ten, we would have gone

screaming out that door to the police station. we looked like a normal american family because we were a normal family. and then everything upended on us. >> your book is called "a serial killer's daughter." is that how you see yourself? >> it's taken me a long time to even be able to say that out loud. but that's the truth. >> reporter: kerri says she's forgiven her father. >> you will always be my baby girl i raised right proud, independent. hopefully someday your heart will mend and you can forgive me. life before the arrest was a good time. and the dark side took me away. >> how could you even correspond with him? i mean, people would wonder, why wouldn't you just cut him off? >> i wasn't corresponding with btk, i'm never corresponding with btk. i'm talking to my father, i'm talking to the man that i lived with and loved for 26 years. i still love my dad today. >> you still love him today?

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finally tonight, kerri rawson recently told abc news she is, quote, still on her journey of healing and forgiveness. she says she faces daily challenges as the daughter of a serial killer and that today she no longer has contact with her father. that's "nightline" for this evening. you can always catch our full episodes on hulu. we'll see you right back here same time next week. thanks for the company, america. have a great weekend. good night.

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