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SUMMARY of FIREARM-GENERATED MARKS on CARTRIDGE CASES. Luke Haag Criminalist Forensic Science Services Carefree, AZ. FIRED CARTRIDGE CASE. EXTRACTOR BITE MARK NOT SHOWN. FIRED CARTRIDGE CASE. EXTRACTOR BITE MARK NOT SHOWN. Representative Semi-Auto Pistol. Slide retracted. breechface.
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SUMMARYofFIREARM-GENERATED MARKSonCARTRIDGE CASES Luke Haag Criminalist Forensic Science Services Carefree, AZ
FIRED CARTRIDGE CASE EXTRACTOR BITE MARK NOT SHOWN
FIRED CARTRIDGE CASE EXTRACTOR BITE MARK NOT SHOWN
Representative Semi-Auto Pistol Slide retracted breechface ejector extractor
REFERENCE RE: FIREARMS IDENTIFICATION by MEANS of the COMPARISON and PERSISTENCE of INDIVIDUAL CHARACTERISTICS in EJECTOR MARKS Schecter, B, Silverwater, H. and M. Etzion, “Extended Firing of a Galil Assault Rifle”, AFTE Journal, Vol. 24, No. 1 (Jan. 1992), pp. 37-45 Summary: These authors at the Israeli National Police Laboratory specifically studied the ejector mark produced by one of these rifles as a means of identification since the bolt assembly (which includes the firing pin and extractor) can easily be replaced but the ejector cannot. This was of concern because a knowledgeable person (soldier) who used one of these firearms to commit a crime might exchange the bolt from the crime rifle with the bolt from some other rifle in the inventory and thereby defeat normal firearms identification. The authors were able to demonstrate that the ejector produced a unique and identifiable impression in fired cartridge cases, and that these could still be matched under the forensic comparison microscope after as many as 7000 shots.