Special sessions will also be held to discuss the Interior Ministry's efforts in countering terrorism, including one about examining some of the homemade weapons and ammunitions seized by police and will feature Captain Reem Swar, the head of the Firearms and Toolmarks
Section at Forensic Science Laboratory.
Chapter 2 discusses physical evidence and provides a basic introduction to different types of evidence that a CSI may encounter at a scene, such as fingerprints, trace evidence, firearm and toolmarks
, biological evidence, chemical evidence, and more.
Seven years later, another comprehensive report--this one authored by PCAST--assessed the scientific foundations of a number of feature comparison forensic practices, including forensic comparison of latent fingerprints, bitemarks, toolmarks
, shoe prints, hair taken from a crime scene, and firearms identification.
Looking through either end of a barrel with our naked (or spectacled or contact-lensed) eye reveals very little information, except whether the rifling right behind the muzzle is copper fouled or the bore is really rough, whether due to toolmarks
, corrosion, or erosion.
The work was so well done that it takes a good eye and good light to see the change in the toolmarks
, but you can see which have been machined, and which have not.
Firearms analysis seeks "to determine whether ammunition is or is not associated with a specific firearm based on toolmarks
produced by guns on the ammunition." (177) The methodology "is based on the idea that the toolmarks
produced by different firearms vary substantially enough...
(267) After surveying the literature on uniqueness, reproducibility, and permanence of individual characteristics, the report noted that "[m]ost of these studies are limited in scale and have been conducted by firearms examiners (and examiners in training) in state and local law enforcement laboratories as adjuncts to their regular casework." (268) The report found that the "validity of the fundamental assumptions of uniqueness and reproducibility of firearms-related toolmarks
has not yet been fully demonstrated." (269) The report went on to caution:
One of the PFSA's achievements was the recent international accreditation in firearms and toolmarks
, meaning the evidence analysed at the authority could be admissible in other countries, including Europe.
The Scientific Working Group for Firearms and Toolmarks
advises that similar weapon and ammunition be used for distance tests to reproduce residue patterns accurately (Scientific Working Group for Firearms and Toolmarks
Crime labs still handle far more requests relating to traditional forensic methods--such as comparing ballistics, latent fingerprints, fibers, and toolmarks
. (22) As the high-profile dispute between the federal government and Apple over unlocking a smartphone indicates, digital forensics is an increasingly prominent type of analysis.
As the war progressed, Sauer simplified the markings, stopped polishing out the toolmarks
and deleted the safety.