>> reporter: fredericks testified that gil's car was as close a match as he could find to the one in the security video -- a 2010 nissan pathfinder. and he told the jury one more important detail. the s-u-v in the video had a fog light defect, one that cast a distinct headlight pattern. >> what we're seeing from this vehicle is that it has this white light that is on the ground that moves in front of the vehicle. >> reporter: detectives tracked down gil's white s-u-v -- which he sold a few weeks after tom's death -- and drove it along the same route seen in the security footage. >> and sure enough, when we went out to the scene then -- when we did our tests, we turned the lights on and there was the pattern that was quite visible. >> reporter: gil's car had the same defect visible in the video. prosecutors thought it was just what they needed to place gil at the crime scene and tie all their evidence together. >> that was a unique feature to that vehicle. and it was still exactly the same a year later.