Module Five: Text Questions
Review Questions 1. What is the NIBIN?
The NIBIN is a network that provides law enforcement agencies around the world with access to the images and information. 2. What is rifling? What two types of markings does this produce?
A rifling is a given spiral grooves by the manufacturer. This rifling or spiral grooves cut into the barrel of a gun in order to make a bullet spin as it is fired. Rifling produces grooves and lands. 3. What is a distance determination? How is this done?
A distance determination is the process of estimating the distance between where a shot is fired and its target. This is often done by looking at the patterns of powder residue and the shot pattern. When a gun is shot, traces of gunpowder travel out of the barrel of the gun with the bullet in the direction that the bullet is traveling in. If the end of the gun or muzzle is close to the target, some of this gunpowder residue will be transferred to the target. The pattern or distribution of the residue helps forensic scientists estimate the distance of the gun from the target. 4. What is the Greiss Test?
The Greiss Test uses chemicals to develop gunpowder residue patterns, particularly around bullet holes. 5. When a bullet is retrieved, how is it marked for identification purposes? What should be avoided?
Once a bullet has been retrieved, it is usually marked with the investigator’s initials, often at the tip or base of the bullet. The sides of the bullet should not be marked. Care has to be taken that this mark does not cover or obscure any striations or markings on the bullet.
Critical Thinking Questions 1. If you found a firearm at a crime scene, what steps would you take in order to transport the weapon to the lab?
First I’d make a note about the position of the gun’s safety and hammer. Then I would need to unload the gun before it is transported or handled in analysis. Finally I’d