There are no trifles in forensics, especially when it comes to admitting guilt to a crime. A team of scientists from Flinders University (Australia) has developed a new method for analyzing gunpowder traces, which allows you to identify the smallest remains of gunpowder and identify them with a specific type of ammunition.
Ballistics is one of the most important forensic disciplines. Until now, with its help, it was possible to find out from which weapon the shot was fired, the distance of the shot and the characteristics of the weapon lubricant, following the tracks on the bullet.
Equally important are the residues of by-products from the combustion of ammunition, since over time they can be identified with a specific weapon and its owner. Previously, they were detected by simple chemical analyzes, and more recently, more modern techniques have been developed, for example, neutron activation, atomic absorption spectrophotometry, atomic force microscopy and scanning electron microscopy.
The "food" for these tests is the remains of the firing products. In modern small arms, complex mixtures of smokeless propellants, primers, flame retardants and other components consisting of mineral and metal compounds are used. Gunpowder usually burns at temperatures above 1000 ° C, turning into carbon dioxide, carbon monoxide or steam. But traces of gunpowder, metals, organics and silica still remain in the form of microscopic nodules.
So scientists developed a method for analyzing glass microparticles caked as a result of a shot. The technology makes it possible to identify a certain type of ammunition with previously unattainable accuracy.
For this, the method of ion mass spectrometry of mean flight time was developed, in which ions are used to scan samples, when not only elements, but even isotopes are determined. By measuring the ratio of these isotopes in glass particles, scientists compare them with isotopes in brands of cartridges, which is comparable in accuracy to fingerprints.