Deck 16: Forensic Aspects of Fire and Explosion Investigation

Question 1

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

A) SEM primer residue detection
B) hand swabs
C) neutron activation analysis
D) dermal nitrate test
E) infrared spectroscopy

Answer 1

A

Question 2

Gun powder residue patterns can be detected by:

A) the Greiss test.
B) IR photograph.
C) both A and B
D) neither A nor B

Answer 2

C

Question 3

When an etching agent is applied to a metal surface in order to restore a removed serial number, the stamped area will dissolve at ________ as the unstamped area.

A) a slower rate
B) a greater rate
C) the same rate

Answer 3

B

Question 4

An element is selective in the frequency of light it will absorb. This selectivity is due to its:

A) proton cloud.
B) atomic number.
C) electron energy levels.
D) atomic mass.
E) number of neutrons.

Question 5

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

A) striation markings.
B) manufacturer's imprint.
C) ejection pattern.
D) caliber markings.
E) investigator's initials.

Question 6

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) making test marks with the suspected tool onto a soft metal surface at the crime scene.
B) taking a photograph and cast of the marks, if necessary.
C) reporting whether a tool found at the scene fit into the tool marks.
D) immediately dusting the tool for fingerprints.
E) packing of tool and tool mark evidence together so that the crime lab personnel knows they are thought to be a matched set.

Question 7

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) chocolate
B) fertilizers
C) cosmetics
D) tobacco
E) urine

Question 8

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) It is not possible to accurately preserve such markings.
E) both A and B

Question 9

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

A) taken to a certified gunsmith for restoration before testing can begin.
B) placed in an air-tight plastic bag.
C) cleaned and dried.
D) transported to the crime lab in a container with enough of the same water necessary to keep it submerged.
E) submitted to crime lab in a paper bag.

Question 10

In atomic absorption chromatography, the amount of light absorbed is ________ to the concentration of the element in the test sample.

A) is not related
B) indirectly related
C) directly related

Question 11

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

A) the presence of grit and rust can to some degree alter the marking on bullets fired through the same barrel.
B) evidence bullets often are distorted on impact and only small areas are found with intact markings.
C) lands and grooves are subject to wear and tear and hence striation markings are susceptible to continuing change.
D) all of the above
E) none of the above

Question 12

A monochromator can consist of a:

A) diffraction grating and slit.
B) prism and slit.
C) ruler
D) both A and B
E) neither A nor B

Question 13

Generally, the gauge of a shotgun is ________ to the diameter of its barrel.

A) directly related
B) indirectly related
C) not related

Question 14

The likelihood of detecting GSR on swabs taken from living subjects more than six hours after a firing has occurred is ________ the likelihood of detecting GSR within two hours of a firing.

A) greater than
B) less than
C) the same as

Question 15

Which is NOT a class characteristic of a suspect's sneaker?

A) color
B) style
C) brand
D) size
E) wear marks

Question 16

The reason grooves are rifled into the bore of a gun is so that a:

A) bullet will be reduced in size before it exits the gun.
B) bullet will be made to spin and hence have a true and accurate course on leaving the barrel.
C) ballistics examiner will have an easier time identifying evidence.
D) manufacturer can put its unique mark on its product.
E) bullet moving through it will have unique striations.

Question 17

Generally speaking, the amount of gun powder particles found around a bullet hole is ________ to the distance from which the weapon was fired.

A) indirectly related
B) directly related
C) not related

Question 18

IBIS is/are:

A) reference database of gunsmiths and retail outlets.
B) trade groups of firearm manufacturers.
C) automated screening tools for firearm evidence.
D) lists of licensed gun dealers.
E) safety education courses for firearm use.

Question 19

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) greater than
B) less than
C) the same as

Question 20

Distinctive markings of shells and cartridges can be made by the:

A) firing pin.
B) extractor and ejector mechanism.
C) magazine.
D) breech lock.
E) all of the above

Question 21

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

A) A shotgun pellet
B) A cartridge casing fired from a shotgun
C) A fired bullet
D) A cartridge casing fired from a handgun
E) All of the above will show markings

Question 22

List common field reagents used to enhance bloody fingerprints.

Question 23

A technique applicable for determining whether an individual has recently fired a weapon is:

A) the scanning electron microscope.
B) atomic absorption analysis.
C) neutron activation analysis.
D) all of the above
E) none of the above

Question 24

The distribution of gunpowder particles and other discharge residues around a bullet hole permits:

A) estimation of the height of the shooter
B) determination of the distance from which the gun was fired
C) determination of the caliber of bullet used
D) determination of the kind of firearm used
E) estimation of the angle of bullet impact

Question 25

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

A) plaster of paris
B) a magnet
C) an electrostatic lifting device
D) imido black dye
E) luminol

Question 26

Explain how a comparison microscope is used to compare bullets and cartridge cases.

Question 27

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

A) class
B) non-comparative
C) wear
D) individual
E) generic

Question 28

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 brand name of the tool.
C) The side or portion of the tool making the impression.
D) The angle at which the tool was held.
E) None of the above

Question 29

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

A) Determining how far from the victim the weapon was held.
B) Determining that two or more cartridge cases were fired from the same weapon.
C) Identifying a bullet as having been combined with a particular shell prior to being discharged.
D) Restoring serial numbers ground off the gun.
E) All of the above can be determined from a laboratory examination of firearm evidence.

Question 30

List and diagram the class characteristics and individual characteristics that are found on a spent bullet.

Question 31

Two elements detected on the hands of an individual who has recently fired a weapon are:

A) barium and antimony.
B) zinc and copper.
C) antimony and iron.
D) iron and lead.
E) barium and nitrates.

Question 32

Which of the following procedures is not to be followed in collecting and packaging firearms evidence at the crime scene?

A) Unloading a weapon before shipping it to the crime laboratory.
B) Avoiding inserting a stick or pencil into the barrel of a weapon.
C) Marking an empty cartridge case on its base for identification.
D) Marking a fired bullet on its base for identification.
E) Making accurate measurements of exact locations where cartridge cases are found.

Question 33

Name and describe the test(s) that investigators use to determine whether an individual has fired a weapon.

Question 34

Describe the various techniques that are used to rifle a barrel.

Question 35

Objects bearing tool marks should either be submitted intact to the crime lab or a ___________ should be taken of the tool mark.

A) cast
B) impression
C) black and white photograph
D) digital photograph
E) film photograph

Question 36

Which of the following statements is true?

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

Question 37

The presence of gunpowder residues on a garment whose color conceals the existence of the residues is best revealed by

A) infrared spectrophotometry.
B) color photography.
C) gas chromatography.
D) infrared photography.
E) ultraviolet photography.

Question 38

Explain how an investigator determines how far a weapon was fired from a target.

Question 39

Explain the concept of the NIBIN database.