Exam 9: Firearms, Tool Marks, and Other Impressions

Briefly describe the sequence of events that occur from the time the trigger of a firearm is pulled to the time the bullet is fired.

To prevent the disturbance of latent fingerprints on a firearm, the weapon should be lifted by:

Match the word in Column 1 to its definition in Column 2. Each answer can only be used once. A)The cut or low-lying portions between the lands in a rifled bore B)An interior constriction placed at or near the muzzle end of a shotgun's barrel to control shot dispersion C)A discipline mainly concerned with determining whether a bullet or cartridge was fired by a particular weapon D)A chemical test used to develop patterns of gunpowder residues around bullet holes E)The rear part of a firearm barrel F)The mechanism in a firearm that throws the cartridge or fired case from the firearm G)The mechanism in a firearm by which a cartridge or fired case is withdrawn from the chamber H)The spiral grooves formed in the bore of a firearm barrel that impart spin to the projectile when it is fired I)The diameter of the bore of a rifled firearm, usually expressed in hundredths of an inch or millimeters J)Size designation of a shotgun, originally the number of lead balls with the same diameter as the barrel that would make a pound. The only exception is the .410 shotgun, in which bore size is 0.41 inch. K)The raised portion between the grooves in a rifled bore L)The interior of a firearm barrel M)The process of determining the distance between the firearm and a target, usually based on the distribution of powder patterns or the spread of a shot pattern -Distance Determination

NIBIN makes the final determination about whether or not two bullets were fired by the same gun.

A wear pattern, cut, gouge, or other damage pattern can impart ________ characteristics to a shoe.

Briefly describe how a firearms examiner makes a distance determination for a handgun or rifle shot.

Bullet wipe consists of a mixture of carbon, dirt, lubricant, primer residue, and ________.

Discernible random nicks and breaks that the tool has acquired through wear and use typically impart ________ characteristics to tool marks.

Match the word in Column 1 to its definition in Column 2. Each answer can only be used once. A)The cut or low-lying portions between the lands in a rifled bore B)An interior constriction placed at or near the muzzle end of a shotgun's barrel to control shot dispersion C)A discipline mainly concerned with determining whether a bullet or cartridge was fired by a particular weapon D)A chemical test used to develop patterns of gunpowder residues around bullet holes E)The rear part of a firearm barrel F)The mechanism in a firearm that throws the cartridge or fired case from the firearm G)The mechanism in a firearm by which a cartridge or fired case is withdrawn from the chamber H)The spiral grooves formed in the bore of a firearm barrel that impart spin to the projectile when it is fired I)The diameter of the bore of a rifled firearm, usually expressed in hundredths of an inch or millimeters J)Size designation of a shotgun, originally the number of lead balls with the same diameter as the barrel that would make a pound. The only exception is the .410 shotgun, in which bore size is 0.41 inch. K)The raised portion between the grooves in a rifled bore L)The interior of a firearm barrel M)The process of determining the distance between the firearm and a target, usually based on the distribution of powder patterns or the spread of a shot pattern -Bore

Which of the following factors is LEAST likely to be considered by the examining tool mark technician?

Match the word in Column 1 to its definition in Column 2. Each answer can only be used once. A)The cut or low-lying portions between the lands in a rifled bore B)An interior constriction placed at or near the muzzle end of a shotgun's barrel to control shot dispersion C)A discipline mainly concerned with determining whether a bullet or cartridge was fired by a particular weapon D)A chemical test used to develop patterns of gunpowder residues around bullet holes E)The rear part of a firearm barrel F)The mechanism in a firearm that throws the cartridge or fired case from the firearm G)The mechanism in a firearm by which a cartridge or fired case is withdrawn from the chamber H)The spiral grooves formed in the bore of a firearm barrel that impart spin to the projectile when it is fired I)The diameter of the bore of a rifled firearm, usually expressed in hundredths of an inch or millimeters J)Size designation of a shotgun, originally the number of lead balls with the same diameter as the barrel that would make a pound. The only exception is the .410 shotgun, in which bore size is 0.41 inch. K)The raised portion between the grooves in a rifled bore L)The interior of a firearm barrel M)The process of determining the distance between the firearm and a target, usually based on the distribution of powder patterns or the spread of a shot pattern -Ejector

________ are the cut or low-lying portions between the lands in a rifled bore.

Two procedures used to preserve impressions that cannot be submitted to the laboratory are lifting and ________.

An imprint may be lifted from a surface at a crime scene using:

Discuss five factors that influence the amount of gunpowder residue deposited on a target.

Distance determination is usually based on the distribution of powder patterns or the spread of a shot pattern.

What chemicals are used to restore an obliterated serial number? What do these chemicals do to reveal the obliterated number?

________ refers to the spiral grooves impressed in the bore of a firearm barrel.

What are two elements detected on the hands of an individual who has recently fired a weapon?

The Griess test is used to determine the presence of ________.