CNN Forensic Files July 16, 2014 07:27:00
>> a tool mark is a characteristic left behind during the process of using a tool to either cut, grind, file or polish a piece of metal. >> there can be hundreds of microscopic tool marks in a pipe used in a homemade gun. when ballistics experts compared the bullets from the victims to those fired from seda's zip gun, the tool marks were microscopically similar. finally police asked seda for a blood sample for dan testing. dna matched that of the letter from the zodiac killer. detectives had the pleasure of telling seda they knew his true identity. >> i put out my hands and said i've been look...
Source: archive.org