paul kayfetz, a photographer and engineer, is an expert in something called photogrammetry. >> it's a $6 word for making measurements from photographs -- or using photographs to make measurements. >> brunn's experts needed a map of the accident scene with the skid marks to conduct their investigation. kayfetz's job was to reproduce the mark on the road in the exact position so a surveyor could map its location. he began by making a 35-milimeter negative of schneider's photograph showing the skid mark. >> i put it into a special camera that i take back to the scene. i locate the exact point from which he took his photograph, and looking through my camera, i can re-mark the position of the skid mark on the ground and have a surveyor record it. >> the chalk marks helped kayfetz verify that the mark was exactly as it appeared in the photo. once the new survey map was created, dr. william blythe, an expert in applied mechanics and accident reconstruction, was able to trace the path of the secret service car. the results confirmed that sinclair's statement, that the secret service cars were