Exam 9: Firearms, Tool Marks, and Other Impressions

Blood enhancement chemicals have been found to negatively impact STR DNA typing; therefore footwear impressions made with blood are not typically analyzed.

Which of the following rifling methods is no longer in use?

When a gun is recovered from an underwater location, it should be:

Gunpowder residue patterns can be detected by:

Shoe and tire marks impressed into soft earth can be best preserved by:

Which of the following is NOT expected to show any evidential marks or impressions?

What makes the final determination about whether or not two bullets were fired by the same gun?

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throws the cartridge or fired case from the firearm G)The mechanism in a firearm by which a cartridge or fired case is withdrawn from the chamber H)The spiral grooves formed in the bore of a firearm barrel that impart spin to the projectile when it is fired I)The diameter of the bore of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 -Grooves

Caliber is a measure of the diameter of the bore of a rifled firearm.

A technique applicable for determining whether or not an individual has recently fired a weapon is:

The comparison of two bullets is possible with the comparison microscope. Such a study is made difficult by the fact that:

How are striations useful for comparing bullets?

If the zone of strain has been removed, or if the area has been impressed with a different strain pattern, the serial number usually can be restored.

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 -Breechface mark

The number of lands and grooves and the width and direction of twist are individual characteristics of a rifled barrel.

Discharged evidence bullets must be carefully handled to avoid damage to the:

Which of the following results is NOT possible from a laboratory examination of firearm evidence?

Name three factors that can prevent a firearms examiner from obtaining a perfect match of striation markings around the periphery of two bullets.

Which technique of detecting gunshot residue holds the most promise for the immediate future?

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 -Griess Test