Lanthanide luminescent markers in hollow-point projectiles to facilitate post-mortem ballistic analysis

Abstract

Hollow-point ammunition represents a substantial segment of the global arms market and is employed by law enforcement agencies in multiple countries. Its widespread adoption is primarily attributed to the greater extent of tissue damage it produces, combined with its reduced likelihood of over-penetration. Upon impacting the human body, the projectile deforms, often undergoing multiple deviations in its trajectory and, in some instances, fragmenting. These ballistic characteristics present significant challenges during autopsy procedures, frequently making it impossible to accurately reconstruct the projectile's path or recover it for subsequent ballistic comparison. In this study, we propose the incorporation of lanthanide-based luminescent markers into the cavities of .40 S&W hollow-point projectiles, which, upon deformation, gradually release these markers. Experimental tests were performed on various target media, including ballistic gelatin, ballistic clay, and fresh porcine hind limbs. In all cases, entrance wound, tissue disruption, and projectile trajectories were clearly visualized using a standard forensic light source. Furthermore, a forensic scenario was simulated involving a victim inside a vehicle. In this scenario, the projectile penetrated the car door and deformed only upon striking the victim's body, thereby releasing the marker. The developed markers do not alter the ballistic performance of the ammunition, are chemically inert, and remain stable under conditions of high temperature and pressure. They can be readily recovered from biological matrices and subsequently analyzed via infrared vibrational spectroscopy. The results of the tests indicate a significant potential for facilitating faster and more accurate autopsy examinations.