been replaying in my head, over and over. it was, all, very unbelievable. it happened on thanksgiving. two teenagers, missing. i just buried my head into my hands, and i started to cry. where they were, and what they did would launch a terrifying case. why did have to happen here? with a deadly end. nobody s leaving until we figure out what happened. a man at home, alone, and afraid. what would you do, if you felt in danger? they were really attacking his home. you have a right to protect your home, and to protect yourself. he planned. he prepared. and he was determined to kill. the most chilling detail of all. what you ll hear on tape. hello and welcome to dateline. growing up, cousins nick brady and haile kifer were close. nick loved to joke, and haile loved to laugh. the teenagers were together that cold, november day, when tragedy struck. the horrible incident was all there for police to hear, on a perfectly-clear recording. so, why was what