How is gunshot residue detected?

Answer by  Qwitzon (578)

First, a sample is collected from the skin. Then, x-ray spectroscopy (or a similar technology that detects elements present in a sample) is used to detect lead, antimony and barium. If they are present and in the right proportions to each other it is a positive. New Scientist, 23 November 200 ran an article on the problems with this test.

Answer by  eyes6 (8)

In most cases, particulates scatter when a gun is fired, leaving behind residue on spent shell casings, the weapon, skin, clothing and basically any other surface that is in close proximity to the weapon when it's fired. Gunshot residue tests for both nitrates and lead and includes specific residue patterns.

Answer by  xazurianx (330)

Modern gunpowder is comprised primarily of potassium nitrate, charcoal, and sulfur. Deposits of this residue, typically nitrate compounds, can be detected using modified gas testing using treated and desensitized photogenic paper. Since the residue isn't readily water-soluble it can't simply be washed from skin or clothing.

Answer by  champaign9497 (11977)

There are multiple ways but if you truly want to know ask someone that deals with Forensics they would know.

Answer by  Swani (125)

There are chemicals that detect if nitrates are present from using a gun. They use a Modified Griess Test which consists of special paper and chemicals. If any residue evidence changes the color of the paper because of the nitrates, the gun would have been fired.

Answer by  elb (1105)

When a gun is fired, the explosion distributes minute particles that derive from the bullet, the gunpowder, the casing and even the gun itself; the particles may be burnt or not. These particles are so small that they aren't visible to the naked eye; electron microscopes and x-ray spectroscopes are used to find them, chemical tests to validate them.

Answer by  jkroller (285)

when certain chemicals are sprayed on spent gunpowder it becomes UV reactive. other solvents may be placed on a cotten tipped stick or q-tip. these chemicals will turn the cotten red when they come into contact with gunpowder.

Answer by  tcat (769)

I believe that it is the gunpowder or a powdery substance left behind by the gunshot blast. I think the police can see it by the naked eye. They allready know what the powdery substance looks like and how to spot it. Or they have have a special kit that helps them pick it up.

Answer by  les59 (852)

There is a chemical that the police use to detect gunshot residue. It turns a certain color in the presence of this residue. I'm not sure what chemical it is, but you could look it up online.