EXCERPTS from BASIC FIREARMS IDENTIFICATION Lucien C. Haag Criminalist Forensic Science Services, Inc. Carefree, AZ 85377 haagfssi@aol.com Prepared for DCA Vince Imbordino

PRINCIPLES OF FIREARMS IDENTIFICATION CALIBER DESIGNATIONS Caliber relates to the nominal inside dimensions of the barrel

PRINCIPLES OF FIREARMS IDENTIFICATION FOUR COMMON RIFLING ARRANGEMENTS Rt 4 5 6 6 Rt Rt Lt Direction of Rotation

PRINCIPLES OF FIREARMS IDENTIFICATION: Class Characteristics Imparted to Fired Bullets RIGHT TWIST LEFT TWIST

Examples of Fired Bullets Right Twist Left Twist

SLIDE SOURCES of MARKS on CARTRIDGE CASES BREECHFACE FIRING PIN EXTRACTOR EJECTOR

breechface extractor SLIDE removed from a Semi-Automatic Pistol Support Area for the Cartridge extractor SLIDE removed from a Semi-Automatic Pistol

Live Cartridge loaded from the Magazine Slide retracted extractor ejector

EJECTOR MARK on an Extracted and Ejected Cartridge Case  ejector mark firing pin impression ejector Impact site Typical ejectors are located at the 7 to 8 o’clock position

barrel slide CARTRIDGE CASE EJECTION from a SEMI-AUTOMATIC PISTOL Ejector slide

STYLIZED BREECHFACES with VARIOUS TOOL MARKS FIRED CARTRIDGES

VARIOUS EJECTOR SHAPES STYLIZED BREECHFACES and VARIOUS EJECTOR SHAPES FIRED CARTRIDGES with EJECTOR MARKS

Summary of Markings on Cartridge Cases

BASIC FIREARM and TOOLMARK IDENTIFICATION -end- Lucien C. Haag Criminalist Forensic Science Services, Inc. P.O. Box 5347 Carefree, AZ 85377 haagfssi@aol.com