detail. it's like an egg on a teflon frying pan. one can see that one achieves a very true representation of the interior of the barrel, plus the fine detail. >> he cut away the portion of the barrel imprint destroyed by the screwdriver and then compared the remainder of the cast to the bullets that killed cliff merck. in an incredible turn of events, they were an exact match. this proved that clifford merck's own gun was used in his murder and that the cowan brothers had been in possession of the gun before it had been altered. even with this discovery, it still wasn't enough to prove murder. >> that was good circumstantial evidence. however, it still did not place them inside the crime scene. >> but there was one more piece of evidence about to be