. >> waseem daker is evil. he's pure evil. he's a monster. >> and that's what lottie told police. she said her stalker must have been the one behind the attack on carmen and nick. but why? daker was obsessed with lottie. he'd never met or even spoken to carmen. or had he? lottie thought she knew the answer. a phone call she says daker made to carmen's phone a few days before the murder. >> it was friday the 20th, and like daker style the calls started coming in and the phone got put off the hook. and then i could hear her phone ringing. >> carmen answered, then hung up abruptly. what was said? nobody knows. but carmen told her sister and brother-in-law that the call was from lottie's stalker. >> she said i'm going to go get a hammer and put it next to the bed. and i remember laughing thinking if that guy decides to get in the house he's in trouble. but you really never think that it would go to where it went. >> we had talked about her packing some stuff and coming to stay with us for a while. >> lottie says se

. >> i have no doubt that waseem daker's a cold-blooded killer and that justice has been served with his conviction. doesn't matter what lottie says. this case is carmine. this case is about nick. >> that's all for this edition of dateline. i'm natalie morales. thank you for watching. >>> i'm craig melvin. >> and i'm natalie morales. >> and this is "dateline". >>> someone just sucks the life out of you and tells you your dream life isn't going to happen, that wedding you're planning, you don't get to have it. evil exists. evil dwells in people. >> it was a night like this just before halloween, a killing that still haunts. >> found him, he's lying there and i couldn't feel a pulse. >> the young dad, engaged to be married, dead on the ground. >> they determined that it was a murder. >> and here is what made this mystery so chilling. the possible suspects were all in costume. >> the cattle boy and the penguin, everybody is dressed as somebody else. how are you going to be able to identify people in? >> cowboy? penguin? costumed killer? sounds like something ripped from the pages of ste