Citation

Haag L. AFTE J. 2021; 53(4): 159-180.

Copyright

(Copyright © 2021, Association of Firearm and Toolmark Examiners)

DOI

unavailable

PMID

unavailable

Abstract

There is a mistaken notion by some that the shooting of automobile tires by one or more police officers will prevent the subject driver from escaping a crime scene in his or her vehicle. Yet one needs merely to watch the television news or one or more police programs to see fleeing suspects driving 'on the rims' with sparks flying and one or more tires effectively destroyed by so-called stop sticks. The perforation of vehicle tires by small arms projectiles produces very characteristic defects in tires which take on two distinct forms depending on whether the bullet is a full metal-jacketed bullet or a hollow point bullet. The hollow point cavity in the latter acts like a cookie-cutter, and punches out a plug of rubber, leaving an obvious hole in the sidewall of the tire. A full metal-jacketed bullet, on the other hand, leaves a barely discernable pinhole in the tire after pushing its way through the rubber. Both events result in the loss of air pressure with the deflation times ranging from seconds with perforations by hollow point bullets, to minutes with full metal-jacketed bullets. Velocity loss values as a result of sidewall perforation by common pistol and rifle bullets are small with such bullets typically retaining 80 to 90% of their impact velocity. Positive results using traditional chemical testing for lead and copper residues around the margins of these defects provides confirmation of causation by a bullet as opposed to punctures by nails, glass, an ice pick, sharp sticks, etc.

Keywords: bullet holes, deflation time, Doppler radar, ricochet, Run Flat tires, sidewall, terminal ballistics, threshold velocity, vehicle tires, velocity loss

Language: en