more shooting reconstruction

Shooting Reconstruction at a Crime Scene 

Utilizing a Trajectory Kit

• centering guides can affect the angle significantly 

Angle of Incidence (Angle of Impact)

• use acute angle 

Types of Barrels

• rifled barrel- barrel of gun can be rifled to put spin on bullet; increases accuracy 

  • inside of barrel has land and grooves 

Cartridge Case

• class evidence 

  • manufacturer 

  • shape

  • caliber

  • composition 

• individual evidence 

  • breech face marks 

  • firing on impressions

  • chamber marks

  • extractor marks

  • ejector marks 

Striations

• tiny scratches on bullet that can be specific to a single gun 

Conclusion of Analysis 

• if class characteristics and striations match, can say the bullet was likely fired by the suspect gun

National Integrated Ballistic Information Network 

• NIBIN

  • specialized computer network in the united states 

  • contains digital images of recover pieces of ballistic evidence 

  • can use information from previous entries to establish connections 

  • associate previously unrelated crimes

    • generates investigative leads, arrests, and convictions 

Integrated Ballistic Identification System 

• IBIS

  • uses sophisticated electronic and optical technology to digitally compare evidence stored in the database 

Discharged Cartridge Case Patterns

• if suspect’s gun is located, may conduct ejection pattern test

• not reliable method