excerpts from basic firearms identification lucien c. haag criminalist forensic science services,...
TRANSCRIPT
EXCERPTSfrom
BASIC FIREARMSIDENTIFICATION
Lucien C. HaagCriminalist
Forensic Science Services, Inc.Carefree, AZ [email protected]
Prepared for DCA Vince Imbordino
PRINCIPLES OF FIREARMS IDENTIFICATIONCALIBER DESIGNATIONS
Caliber relates to the nominal inside dimensions of the barrel
PRINCIPLES OF FIREARMS IDENTIFICATIONFOUR COMMON RIFLING ARRANGEMENTS
4 5 6 6
Direction of Rotation
Rt Rt Rt Lt
PRINCIPLES OF FIREARMS IDENTIFICATION:Class Characteristics Imparted to Fired Bullets
RIGHT TWIST LEFT TWIST
Examples of Fired Bullets
Right Twist Left Twist
SLIDEBREECHFACE
EXTRACTOR FIRING PIN
EJECTOR
SOURCES of MARKS on CARTRIDGE CASES
extractor
breechface
SLIDEremovedfrom aSemi-AutomaticPistol
Support Areafor the
Cartridge
extractor
Live Cartridge loaded from the Magazine
Slide retracted
ejector
ejector
ejector mark firing pin impression
EJECTOR MARK on an Extracted and Ejected Cartridge Case
Impact site
Typical ejectors are locatedat the 7 to 8 o’clock position
CARTRIDGE CASE EJECTION from a SEMI-AUTOMATIC PISTOL
slide
barrel
Ejector
STYLIZED BREECHFACESwith
VARIOUS TOOL MARKS
FIRED CARTRIDGES
STYLIZED BREECHFACESand
VARIOUS EJECTOR SHAPES
FIRED CARTRIDGESwith
EJECTOR MARKS
Summary of Markingson
Cartridge Cases
BASIC FIREARMand
TOOLMARKIDENTIFICATION
Lucien C. HaagCriminalist
Forensic Science Services, Inc.P.O. Box 5347
Carefree, AZ [email protected]
-end-