Misleading Entry Wounds From Atypical Bullet Behavior.

Some pistol bullets exhibit atypical wound ballistic behavior that can result in misleading and misinterpreted entry gunshot wounds. We demonstrate the atypical performance and behavior of these bullets using (1) high-speed videography of projectiles penetrating, perforating, and exiting soft tissue simulants; (2) Doppler radar tracking throughout simulated wound production; (3) downrange witness panels to record postperforation bullet orientation during a secondary impact; (4) laser tracking to assess and compare postperforation bullet deflection; (5) evaluation of "bullet wipe" around entry bullet holes in a victim's clothing; and (6) projectile penetration depth for differentiating primary from secondary gunshot wounds. Truncated cone and certain flat-point full-metal-jacketed pistol bullets in the 3 most common calibers of 9 mm, .40 caliber, and .45 caliber typically perforate the victim with little or no yawing, producing straight wound tracks and continuing to travel nose forward upon exiting. Any secondary gunshot victim downrange sustains a normal-appearing entry wound. Common pistol bullets exiting gunshot victims are typically destabilized and enter a yawing or tumbling flight, resulting in entry wounds that appear as typical, first strike entry wounds when in fact, they are secondary gunshot wounds. However, some bullets retain their nose-forward flight after emerging from a gunshot victim. These secondary but normal-appearing, round-shaped entry wounds may be erroneously identified as direct, primary strikes.