>> in fact, she happened to be sharing her bedroom with a 21-year-old family friend named james matleand a movie and went to bed. >> yeah, that's her story. that's it. >> not exactly a convincing alibi. any more than the obvious fiction that james, a new man in her life, was just a friend. even less convincing, when detective ron elgis learned about a trip to a 7-eleven store, middle of the night, about an hour and a half before the murder. >> why are they hiding little pieces that's seem insignificant to what is going on? then we started to do surveillance on them. now they're starting to get worried because they think we're watching them. >> surveillance photos show dawn with james and her two daughters, brandy, her 13-year-old daughter from a previous marriage, and alyssa, 7 by this time. that's right -- a year into the investigation, little alyssa was back with her biological mom. with ben dead, the courts had slowly weaned her back there permanently. >> so there you are still trying to grieve the loss of ben at the same time as alyssa is being pulled back toward dawn. >> yeah, i lo