Effects of human decomposition on test fired bullet – An experimental research

Abstract

The present experimental research was carried out in the year 2011 in Kingston, Jamaica. A total of six firearms were used in this research, each bullet served as its own control. A total of seven sets of bullets were test fired of which one set was embedded in the body (control) and was stored at 2–4 °C and other six sets were embedded in a fresh cadaver and subjected to environment temperature of 26–29 °C, for a period of 12 days. Macroscopic observation indicated complete corrosion of the class characteristic markings (major countable striations) by the 8th day, by the 6th day it was near obscuration. On the 2nd day with the onset of biofilms, corrosive changes on the rifling marks were noted. On the 4th day, biofilm, and bio-corrosion (microbiologically induced corrosion) had obliterated 100% of linear macroscopic striations (microstriae/individual characters) and 50% of class character rifling marks. The observations through comparison microscope indicated that the individual characteristic (microscopic) markings on the bullet in the form of microstriae showed complete corrosion or obscuring by the 10th day. The surface appeared smooth, onset of corrosion process was noted on the 2nd day and by the 4th day 50% obscuring of the marks was noted. This change in the markings of the metal surface of the bullet was uniform to all the ammunitions used in this study. The control bullets showed no such changes during the period of study. The study confirms the existence of a potential danger in dealing with crime bullets retrieved from putrefied bodies. It also highlights the importance of early retrieval of dead bodies in firearm deaths and the importance of proper storage facilities to deal with cases of firearm deaths.

Keywords

• Bullets
• Biofilm
• Bio-corrosion
• Decomposition
• Class character
• Striae
• Rifling marks