Chapter 4 - Is It a Bullet Hole?

Abstract

This chapter describes various aspects of a bullet hole that includes determining direction of travel and empirical testing. With training and experience, the physical properties of bullet holes and bullet impact sites in most materials are readily distinguishable from defects produced by other objects. The determination is easy when a recognizable projectile is ultimately recovered and the end of a channel in the struck object is known. The use of an area in the evidence material for a test shot is justifiable on the basis of reducing or eliminating variables that could be present when using other seemingly similar materials for such tests. The site in a portion of the evidence material for empirical testing should be chosen and prepared with great care to ensure that subsequent tests do not alter or compromise the actual evidence site. In the absence of an embedded bullet, the transference of bullet metal and bullet wipe to the margins of many bullet holes and impact sites provides a means of verification through chemical or instrumental methods. Empirical testing with comparable ammunition offers a useful and graphic way to illustrate the specific properties of bullet holes or impact sites in the evidence material.