- 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
Test Procedure
Home > Gunshot Residue and Distance Determination > Examination > Chemical Testing > Test Procedure
The Dithiooxamide Test is carried out as follows:
- Confirm performance of all preliminary examinations and tests.
The Modified Griess Test must be performed before this test. - Place a test mark on the item to be tested.
Using a piece of known copper, place the mark well away from any holes to be tested. (Note: Apply the following steps to the test mark first to ensure the reagents are reacting properly and then apply to the questioned area.) - Position the area to be tested.
Place the test mark or suspected bullet hole face up on a clean uncontaminated surface. - Perform color test.
Place three drops of ammonium hydroxide solution on one half of folded filter paper.- Place the moistened half of the filter paper against the test area.
- Fold the dry half of filter paper over the moistened half. Using moderate pressure, press fingertips on the dry half of the filter paper for five to ten seconds.
- Turn the filter paper over.
- Place two or three drops of the dithiooxamide solution on the area that was in contact with the test area.
- Examine and interpret results.
Dark gray-green color indicates the presence of copper-bearing material.
Blue-pink color indicates the presence of nickel (e.g., silver-tipped bullets). - Dry test item.
Allow tested item to dry out before additional testing.
| Note: |
| Because this test is a lifting technique and is not carried out directly on the test item, it is inconsequential if the tested item is dark green or some other dark color. |
Click here to watch a video on the Dithiooxamide procedure
