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.
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