Quiz 9: Firearms, Tool Marks, and Other Impressions

The barrel of a shotgun: A)Is indistinguishable from that of a rifle. B)Is smooth without the grooves and lands found in rifles. C)Is generally shorter than that of a rifle. D)Is wider at the end to concentrate the shot.

The reason grooves are rifled into the bore of a gun is so that a: A)Bullet will be made to spin and have a true and accurate course on leaving the barrel. B)Bullet moving through will have unique striations. C)Manufacturer can put its unique mark on its product. D)Bullet will be reduced in size before it exits the gun.

The comparison of two bullets is possible with the comparison microscope. Such a study is made difficult by the fact that: A)Lands and grooves are subject to wear and tear, so markings are susceptible to continuing change. B)Often evidence bullets are distorted on impact and only small areas are found with intact markings. C)The presence of grit and rust can, to some degree, alter the markings on bullets fired through the same barrel. D)All of the above.

Generally, the gauge of a shotgun is ________ to the diameter of its barrel. A)Directly related B)Not related C)Indirectly related D)None of the above

Distinctive markings of shells and cartridges can be made by the: A)Extractor and ejector mechanism. B)Firing pin. C)Breechface mark. D)All of the above.

What is NIBIN? A)Trade groups of firearms manufacturers B)Safety education courses for firearm use C)A database for firearm evidence D)Lists of licensed gun dealers

Generally speaking, the amount of gunpowder particles found around a bullet hole is ________ to the distance from which the weapon was fired. A)Indirectly related B)Not related C)Directly related D)None of the above

Gunpowder residue patterns can be detected by: A)The Griess Test. B)IR photograph. C)Both A and B D)Neither A nor B

Chokes are sometimes found on shotguns where they function to constrict the end of the barrel. The speed and distance traveled by pellets fired from a narrow choke is ________ the speed and distance traveled by pellets fired from a shotgun with a wide choke. A)The same as B)Greater than C)Less than D)None of the above

The "dermal nitrate test" has fallen into disfavor because of its lack of specificity. Which of the following common materials does NOT give a misleading positive reaction to this test? A)Tobacco B)Chocolate C)Urine D)Cosmetics

The likelihood of detecting gunshot residue on swabs taken from living subjects more than six hours after a firing has occurred is ________ the likelihood of detecting gunshot residue within two hours of a firing. A)The same as B)Less than C)Greater than D)None of the above

Which technique of detecting gunshot residue holds the most promise for the immediate future? A)Infrared spectroscopy B)SEM primer residue detection C)Neutron activation analysis D)Dermal nitrate test

When an etching agent is applied to a metal surface in order to restore a removed serial number, the stamped area will dissolve at ________ the unstamped area. A)A greater rate than B)The same rate as C)A slower rate than D)None of the above

To prevent the disturbance of latent fingerprints on a firearm, the weapon should be lifted by: A)Inserting a pencil into the barrel B)Using disposable forceps C)The outside of the barrel or the trigger D)The edge of the trigger guard or by the checkered portion of the grip

When a gun is recovered from an underwater location, it should be: A)Transported to the crime lab in a container with enough of the same water necessary to keep it submerged. B)Placed in an airtight plastic bag. C)Cleaned and dried. D)Submitted to the crime lab in a paper bag.

Discharged evidence bullets must be carefully handled to avoid damage to the: A)Manufacturer's imprint. B)Caliber markings. C)Striation markings. D)Ejection pattern.

Tools and tool marks are often found at burglary scenes and can be useful evidence. Proper evidence collection by the field investigator would include: A)Reporting whether a tool found at the crime scene fit into the tool marks. B)Making test marks with the suspected tool onto a soft metal surface at the crime scene. C)Taking a photograph and cast of the marks if necessary. D)Packing of tool and tool mark evidence together so that the crime lab personnel know they are thought to be a matched set.

Two-dimensional imprints found at a crime scene can be lifted using: A)Photographic paper. B)A silicone casting medium. C)A scanning electron lifter. D)An electrostatic lifting device.

Shoe and tire marks impressed into soft earth can be best preserved by: A)Photographing and casting with dental stone. B)Photographing and then use of the electrostatic lifting technique. C)Casting with dental stone and then attempting the electrostatic lift technique. D)Both A and B

Which is NOT a class characteristic of a suspect's sneaker? A)Wear marks B)Brand C)Color D)Size

Which of the following is NOT expected to show any evidential marks or impressions? A)A fired bullet B)A cartridge casing fired from a handgun C)A cartridge casing fired from a shotgun D)A shotgun pellet

What are two elements detected on the hands of an individual who has recently fired a weapon? A)Zinc and copper B)Antimony and barium C)Barium and nitrates D)Antimony and iron

Which of the following factors is LEAST likely to be considered by the examining tool mark technician? A)The direction of the tool movement as it passes over the surface B)The side or portion of the tool making the impression C)The brand name of the tool D)The angle at which the tool was held

Which of the following results is NOT possible from a laboratory examination of firearm evidence? A)Determining that two or more cartridge cases were fired from the same weapon B)Determining how far from the victim the weapon was held C)Restoring serial numbers ground off the gun D)Identifying a bullet as having been combined with a particular shell prior to being discharged

Which of the following statements is true? A)A bullet can be individualized to a weapon by the number and twist of its lands and grooves. B)The comparison microscope is an indispensable tool of the firearm examiner. C)The diameter of the bore of a rifled firearm is its gauge. D)Carbonaceous smoke or soot deposited around a bullet hole is normally indicative of a discharge 12 to 18 feet or less from the target.

The presence of gunpowder residues on a garment whose color conceals the existence of the residue is best revealed by: A)Infrared photography. B)Ultraviolet photography. C)Color photography. D)Infrared spectrophotometry.

Which of the following rifling methods is no longer in use? A)The button method B)The hook cutter method C)The mandrel method D)The broach cutter method

What makes the final determination about whether or not two bullets were fired by the same gun? A)IBIS B)A comparison microscope C)NIBIN D)A trained firearms examiner

What is the automated shoe print identification system? A)SICAR B)NIBIN C)ATF D)IBIS

Dust imprints found at a crime scene can be lifted using: A)Photographic paper. B)A silicone casting medium. C)A scanning electron lifter. D)An electrostatic lifting device.

A technique applicable for determining whether or not an individual has recently fired a weapon is: A)Neutron activation analysis. B)Atomic absorption analysis. C)The scanning electron microscope. D)All of the above

Objects bearing tool marks should either be submitted intact to the crime lab or a ________ should be taken of the tool mark. A)Digital photograph B)Film photograph C)Black and white photograph D)Cast

A wear pattern, cut, gouge, or other damage pattern can impart ________ characteristics to a shoe. A)Class B)Wear C)Individual D)Generic

An imprint may be lifted from a surface at a crime scene using: A)Plaster of paris. B)Luminol. C)Imido black dye. D)An electrostatic lifting device.

The distribution of gunpowder particles and other discharge residues around a bullet hole permits: A)Determination of the distance from which the gun was fired. B)Determination of the kind of firearm used. C)Estimation of the angle of bullet impact. D)Estimation of the height of the shooter.

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

The hook cutter rifling method is still used today.

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

Unlike handguns, a shotgun is not rifled.

Shotgun shells are not impressed with any characteristic markings that can be used to compare two shotgun shells to determine if they were fired from the same weapon.

The parts of a firearm that leave impressions on a cartridge case that constitute class characteristics of that weapon are the firing pin, the breechface mark, the ejector, and the extractor.

NIBIN is the National Integrated Ballistics Information Network, a unified firearms search system that incorporates both DRUGFIRE and IBIS technologies.

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

A distance determination can be estimated by measuring the spread of the discharged shot.

As the distance to the target of a shotgun blast decreases, the pellets separate and spread out.

Shortly after a weapon is fired, residues are most likely to be deposited on the thumb web and the back of the firing hand of a shooter.

The SEM approach for primer residue detection is its enhanced specificity over hand swabbing.

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.

It is acceptable to pick up a firearm by inserting an object into its barrel.

A weapon recovered from underwater should be transported to the laboratory in a receptacle containing enough of the same water in which it was found to keep it submerged.

When removal of the original tool mark is impractical, the criminalist photographs the marked area to scale and makes a cast of the mark.

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

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

A compound microscope permits the user to view two separate specimens side-by-side.

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

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

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

________ are markings impressed into the metal of a barrel.

The ________ microscope is the firearms examiner's most important tool because it allows two bullets to be observed and compared simultaneously.

The higher a shotgun's gauge, the ________ the diameter of its barrel.

DRUGFIRE was developed by the ________.

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

Barrel length, caliber, type of ammunition, the type of weapon fired, and the condition of the weapon are all factors that influence the amount of ________ residue deposited on a target.

The ________ the choke, the narrower the spread pattern of the pellets and the faster and farther the pellets will travel.

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

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

Before any impression is moved or otherwise handled, it must be ________ to show all the observable details of the impression.

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

Distance determination is the process of determining the distance between the ________ and a target.

Protection of class and individual markings on ________ and cartridge cases is the primary concern of the field investigator when recovering bullets and cartridge casings.

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

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

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 -Caliber

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 -Choke

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

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

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 -Extractor

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 -Firearms Identification

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 -Gauge

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

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

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 -Lands

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 -Rifling

How are striations useful for comparing bullets?

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

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.

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

What is SICAR and how is it useful in comparing impressions?

Name and briefly describe two popular approaches for collecting gunshot residue from a suspect's hands. What is the logical next step in analysis for these collected samples?

Name one possible class characteristic and one possible individual characteristic that on a bullet, a tool mark, and a footwear impression.

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

What two methods are used to preserve shoe and tire marks impressed into soft earth? Why is it important to conduct both procedures on the impression?

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

For each of the impressions listed below, determine which characteristics are class characteristics and which are individual characteristics. a. Screwdriver pry mark: 0.5 inch wide, filings of stainless steel imbedded in mark, rounded edges, center half-circle groove, 3 wide striations near one edge, 7 narrow striations near one edge b. Two-dimensional footwear impression: Nike brand, 11 inches long, wear pattern on back outside edge, 4 inches wide at arch, gouge at back heel, "Nike Air" imprinted on arch c. Recovered bullet: .22 caliber, deep striation in one land, left-handed twist, 13 fine striations in one groove, 5 grooves around periphery, 79% lead composition

From each of the following descriptions of bullet holes, estimate the distance from the shooter to the target. a. A few widely scattered gunpowder particles with no soot around the entrance hole b. A dark ring around the bullet hole, but no soot or gunpowder particles c. A halo of soot surrounding the entrance hole along with scattered specks of powder grains d. Scorch marks and melted fibers surrounding the entrance hole