Pozzolo and the stub test, how it works and when it should be done

The test to check for residues on the hands after a shot has been fired

Emanuele Pozzolo, the Fratelli d’Italia deputy at the center of the story linked to a gunshot fired during a New Year’s Eve party, underwent the stub test. What does the test consist of? How does it work? The test, carried out in a case in which at least one gunshot was fired, aims to verify the possible presence of gunpowder residues on a subject’s hand.

The test involves the use of an adhesive swab – Stub – to collect any residues and then the use of an electron microscope and an X-ray microprobe to proceed with the analyses. The Stub at the ends is equipped with an adhesive capable of capturing the substances present on both hands, particularly in the areas between the thumb and forefinger, which are most exposed in the event of a shot exploding. The collected samples are then analyzed, the aim of the specialists is to identify any traces of lead, antimony and barium alloy produced by the weapon. The substances are often present in minimal quantities and, due to their characteristics, tend to disappear when – for example – you wash your hands. For this reason, the test should be carried out close to the explosion of the shot.