Citation

Aliste M, Chávez LG. Forensic Sci. Int. 2016; 261: 14-18.

Affiliation

Policía de Investigaciones de Chile (PDI), Laboratorio de Criminalística Regional La Serena, Chile.

Copyright

(Copyright © 2016, Elsevier Publishing)

DOI

10.1016/j.forsciint.2016.01.034

PMID

26874050

Abstract

When a gun is fired, the majority of gunshot residues are deposited on the shooter's hands. But these residues disappear through contact with surfaces or washing. Therefore, the maximum time frame to find GSR on a suspect's hands is 8h. The mucus, inside of a nostril, forms a surface layer where they are trapped foreign particles. In this way, mucus inside of a gunshot suspect's nostrils could act like an adhesive medium to stick on it gaseous particles from a gunshot. In this study, the presence of GSR in nasal mucus and its residence time is examined. A new procedure for the sampling of possible gunshot residue accumulated in the nasal mucus is designed. Samples are taken with cotton swabs moistened with a solution of EDTA and, after an acid digestion, are analysed by graphite furnace atomic absorption spectrometry. In addition, samples of hands are taken for comparison purposes. GSR recovery has been successful. The concentration of GSR in nasal mucus is found to be lower than on the hands, but with a longer residence time. Thus, it is possible to expand the sampling time of a suspect also, as nasal mucus cannot be contaminated by handling weapons.

Language: en