what possible motive could bobby lowe have to want dee dee dead or out of the picture? here was no motive that i could determine whatsoever. >> reporter: and lowe provided investigators with two important clues. first, he said, while he was at dee dee's that night, her dogs had all started barking at something outside as if someone were lurking. and the next morning, he discovered someone had keyed the side of his ford explorer, leaving a long scratch. >> reporter: which suggests somebody is following them on that date? >> absolutely. that's what it meant to me. >> reporter: but who was following dee dee and bobby? who was that angry? that act of vandalism pointed away from bobby lowe. >> i was an variation for several years and i've never known anybody to vandalize their own car. >> reporter: that kind of thinking would make it a perfect alibi. >> sure. sure. if he is sophisticated enough but his background indicated that, you know, he was well-liked guy, kind of successful himself and didn't have a lot of enemies. >> reporter: and then even as investigators looked at s