- 01: Introduction
- 02: History
- 03: Propellants, Firearms, and Ammunition Development
- 04: Modern Firearms Manufacture
- 05: Small Arms Ammunition
- 06: Evidence Handling Procedures
- 07: Equipment and Instrumentation
- 08: Examination of Firearms
- 09: Cartridge and Shotshell Examination
- 10: Characterization and Evaluation of Fired Projectiles
- 11: Bullet Comparison and Identification
- 12: Gunshot Residue and Distance Determination
- Introduction
- Objectives
- AFTE Knowledge and Ability Factors
- Powders and Residues
- Examination
- Distance Determination
- Significance of Results
- Contact Shot
- Nitrite Residues
- Vaporous Lead Residues
- Residues Consistent with the Passage of a Bullet
- Residues Consistent with the Discharge of a Firearm
- Interpretation Challenges
- Reproduction of Results
- Nitrite Residue Patterns
- Shot Patterning
- Chemical Testing
- Shot Pattern Reproduction
- Selected Bibliography
- 13: Toolmark Identification
- 14: Communicating Results
- Resources
Objectives
Home > Gunshot Residue and Distance Determination > Objectives
At the conclusion of this module the student should be able to do the following:
- Describe in general terms the chemical reaction that takes place when propellant powder burns
- Describe the visual and microscopic examination of evidence for the presence of visible gunshot residues
- Describe the physical effects caused by the discharge of a firearm and the passage of a bullet
- Describe the techniques for preparation of test media and chemical reagents required for the Modified Griess Test
- Describe the techniques for preparation of test media and chemical reagents for the Dithiooxamide Test
- Describe the techniques for preparation of test media and chemical reagents for the Sodium Rhodizonate Test
- Explain the chemical reactions that take place in the Modified Griess Test
- Explain the chemical reactions that take place in the Sodium Rhodizonate Test
- Explain the chemical reactions that take place in the Dithiooxamide Test
- Describe the performance of the Modified Griess Test for the detection of nitrite residues on porous objects
- Describe the performance of the reverse Modified Griess Test for the detection of nitrite residues on nonporous objects
- Describe the performance of the Dithiooxamide Test for nickel or cuprous materials
- Describe the performance of the Sodium Rhodizonate Test for the detection of lead residues
- Describe the performance of the Bashinski Transfer Technique/Sodium Rhodizonate Test for the detection of lead residues on darker (blue, black, violet) surfaces
- Describe how to document gunshot residue test/technique procedures and results
- Describe the process of reproducing positive results in gunshot residue examinations
- Articulate conclusions based on gunshot residue test/technique results and the accumulated raw data represented in contemporaneous notes
