ABSTRACT
Under the right conditions, cartridge case locations can provide useful information as to the probable shooter position(s). A number of variables are associated with how a particular weapon ejects red cartridge cases. ese variables include:
• Weapon design • Weapon condition • Ammunition type • Position weapon is held in when red • Movement of weapon during ring • How tightly the weapon is held during ring • Type of terrain shooting occurs on • Presence of obstacles in the scene
A typical cartridge case ejection is shown in Figure 8.1. What must be determined in a shooting incident in which there are ejected cartridge
cases is how many of these variables are unknown and what eect, if any, might there be by not having information about those variables. For example, if red cartridge cases are found at a shooting scene but no gun is recovered, no meaningful results can be obtained by carrying out cartridge case ejection testing with some weapon selected at random. Although it might be possible, from the markings le on the cartridge cases, to predict a possible weapon, tests must be carried out using the particular weapon and similar ammunition (i.e., from the same lot if possible).
