>> things like that don't happen in rowlett, texas. to be a challenge for the rowlett police department. they don't have the experience that a much larger police force might have. >> obviously somebody committed the crime. the question is who? >> there's an intriguing bloody finger print near the murders. >> doesn't match darlie, doesn't match her husband, doesn't match the kids. >> and so the real mystery is, whose print is that? >> one of the theories is that this was a botched burglary. darin had been having trouble with his jaguar, and it had broken down that day, so the jaguar wasn't in the driveway, and darlie's pathfinder wasn't either. if it's true this was a botched burglary, the fact that the cars weren't where they usually were could have indicated to them that the house was vacant. >> it turns out the day of the murder, a neighbor had reported a suspicious black car in the area. >> about seven or eight days before the murder, there was a black car sitting directly in front of my sidewalk. i saw this person's head turned, wa