The Griess test uses chemicals to develop gunpowder residue patterns, particularly around bullet holes.
It is a scientific chemistry test which identifies the proximity of nitrite ion in liquid. One of its most significant applications is obtaining nitrite in drinking water. The test has also been extensively applied for the exposure of trace explosives comprising nitro groups. It is essential to release the nitrate ion from the nuclear explosive before the examination. This is commonly done by alkaline hydrolysis.