Transcript for Waseem Daker: From Stalker to Murderer
You probably have a decent idea of what a stalker usually does, incessant phone calls, harassing e-mails, hanging around where they're not wanted. What about using handcuffs and rope and an ice pick, then you move from someone who needs to get a life to someone who could take a life. And that's what we saw this week in a court case that just ended, but what you didn't get to see until tonight was the woman whose life became a living hell at the hands of someone she thought was her friend. In atlanta a bizarre trial captures the public's imagination. The testimony is still happening. A bizarre murder trial -- in a cobb county murder case today. Reporter: Waseem daker, stalker in the extreme, who haunted a single mother. Just last week, on trial for a brutal murder of a friend and the stabbing of a 5-year-old boy. A courtroom shock as daker represents himself just feet from the woman he terrorized for years. On the stand his victim's face covered to hide her identity and her fear. You ever tell mr. Evans about -- yes. Reporter: But now for the first time, lottie spencer comes forward to "20/20" determined to be a victim no more. I didn't want him to have any more power over me. I don't want him to ever think that he does. Reporter: Her story begins when lottie is 29 years old. The single mother is living outside atlanta, georgia. I couldn't have asked for a better daughter or life. Life was just amazing. We had fun. Every day we had fun. Reporter: She works in a medical office, and on weekends she enjoys paintball where she meets a 17-year-old player named waseem daker. Of syrian descent, daker is highly intelligent, starting college at just 16, but socially awkward. They strike up a conversation about paintball that soon turns personal. He had a lot of problems at school, in relationships that he's had at home, and he began sharing those difficulties and problems with me. Reporter: How did you take that? At that time I just thought it was normal. I thought, everybody has problems, everybody has issues, you know. Reporter: Lottie says she tries to take on a big sister role, but wasseem daker wants more. Reporter: What was the nature of this relationship? Was it romantic? Never. We were friendly because we were on the same team, that's it. Nothing else. Reporter: So the idea that it was romantic only existed in one person's head. Until he started spreading those seeds in other people's heads on the team. And when I found that out, i confronted him. He denied it, and I called his mom, and I spoke to his brother about it and other people about it, and they said, we don't believe it anyways, he's -- you know, he's sick. He just wants to be in a relationship with you, and he can't have you, and he's delusional. Reporter: Those words would prove terrifyingly true. The more lottie pushes him away, the more desperate daker becomes, saying anything to get her attention. Hello. We're not talking even ten phone calls a day, we're talking, you know, 50, 100 phone calls in a day, just the phone constantly ringing. And if I wouldn't pick up, then he would bang on the door just all hours every day. Reporter: When did it occur to you, this isn't just weird, this just isn't intense, I have a stalker? It kind of click ed one day my daughter and I were eating at a wendy's, and he just walks up, and he goes, "wow." He goes, "we have so much in common." And I was thinking, oh, my god, because before that, he would show up at the store, blockbuster, just everywhere. And it hits you. It hits me hard. Reporter: What she doesn't know is that he is not just some confused kid -- waseem daker has stalked other women since he was 14, and now he has lottie in his sights. Daker starts to follow her, lurks outside her office, then an ominous turn. Daker calls lottie at work and says he is in her house, in her daughter's bedroom. Lottie calls the cops. They search the house and find no one, but when she gets home -- he was hiding in my daughter's closet. He came out with a gun. Had it to me first and then had it to him. And I talked him into putting it down. And I called his mom, and his mom and brother came and got him and got the gun. Reporter: Did you call the police and say, this is what happened, this guy had a -- no, I department. Reporter: Why not? I wanted him to get help. I wanted him to stop, and his family constantly would reassure me that he would stop. Reporter: Lottie records several phone calls urging daker to get help. You need help. You need to be committed, okay? Because I need it to stop. I have been trying to help you. I don't want you to commit suicide. Then what -- then I need to ask you, do you want to help me? Do you want to keep me out of ja jail? Reporter: But daker is clearly obsessed. About the middle of february, it was really bad. Banging on my door, all night, calling. It was really bad. And he threatened my life and my daughter's life. He said that he could get away with the perfect murder. He went crazy. Reporter: His relentless pursuit pushes lottie to the breaking point. I was crumbling. I mean, my entire personality was changing. I was really depressed and didn't want to leave the house. I was tired. I could hardly even work at work because I would go days without sleeping. Reporter: Because you were afraid of who was outside. He was outside. He was outside. He was there yelling, banging on the door. Reporter: Finally, she calls the police. So you have him arrested. Mm-hmm. Reporter: You have a restraining order. Mm-hmm. Reporter: But then you decide not to pursue the charges. Mm-hmm. Reporter: Because? His mom and -- called me and assured me that she would get him help now. I was not out to get him into trouble. I wanted just to be able to drive without him being there. I wanted to be able to walk in my door without my door banging a minute after I arrived or my phone ringing as soon as i arrived. I just wanted my life back. Reporter: But it was not to be. Daker shows up at her office in violation of that order of protection. He is arrested, and the court orders him to seek treatment at this mental facility. Lottie takes no chances and moves with her young daughter across town into this Her downstairs neighbor is a flight attendant named karmen smith. She and her 5-year-old son nickolas become much-needed friends. Our children played. Whenever nick and christina were there, they, they played daily. I know that christina just loved nick, and I know that nick just really loved christina. He'd always every day, "can i play with christina?" And it was nice. Reporter: With daker institutionalized, lottie was just starting to feel safe, but that feeling would not last. I knew when he was released, because he had gotten into my car and put the emergency brake up and slid my seat back, and I knew. Oh, my god, he's out. reporter: DETECTIVE John dawes worked the case. Her car was broken into at her workplace in fulton county, and that's where we believe he learned her address that she had written in an address book. Reporter: Daker now knows where lottie is. And in october he takes it to a darker level. Unable to reach lottie on the phone, he calls her friend, karmen smith. Her phone rang, and she came running up the stairs, and I ran over and opened up the door, and she says, "your stalker is calling me." Reporter: Was karmen worried? Oh, my gosh, she was terrified. She was very, very scared. Reporter: The stalking had been going on for almost a year, but lottie could have never imagined what daker would do next.
This transcript has been automatically generated and may not be 100% accurate.