Criminalistics Chapter 8

The [blank] is the original part of the bore left after rifling grooves are formed.

lands

The diameter of the gun barrel is know as its [blank].

caliber

T/F : The number of lands and grooves is a class characteristic of a barrel.

True

The [blank] characteristics of a rifled barrel are formed by striations impressed into the barrel's surface.

individual

The most important instrument for comparing bullets is the [blank].

comparison microscope

To make a match between a test bullet and a recovered bullet, the land and grooves of the test and evidence bullet must have identical widths, and the longitudinal [blank] on each must coincide.

striations

T/F : It is always possible determine the make of a weapon by examining a bullet it fired.

False

A shotgun has a [blank] barrel.

smooth

The diameter of a shotgun barrel is expressed by the term [blank].

guage

T/F : Shotgun pellets can be individualized to a single weapon.

False

T/F : A cartridge case can be individualized to a single weapon.

True

The automated firearms search system developed by the FBI and ATF as a unified system of incorporating both drugfire and IBIS technologies available in prior years is known as [blank].

NIBIN

T/F : The distribution of gunpowder particles and other discharge resides around a bullet hole permits an approximate determination of the distance from which the gun was fired.

True

T/F : Without the benefit of a weapon, an examiner can make an exact determination of firing distance.

False

A halo of vaporous lead (smoke) deposited around a bullet hole normally indicates a discharge [blank] to [blank] inches from the target.

12/18

If a firearm has been fired more than 3 feet from a target, usually no residue is deposited but a dark ring, know as a [blank], is observed.

bullet wipe

As a rule of thumb, the spread in the pattern made by a 12-gauge shotgun increases 1in for every [blank] of distance from the target.

yard

A [blank] photograph may help visualize gunpowder deposits around a target.

infrared

T/F : One test method for locating powder residues involves transferring particles embedded on the target surface to chemically treated photographic paper.

True

Current methods for identifying a shooter rely on the detection of [blank] residues on the hands.

gunpowder primer

Determining whether an individual has fired a weapon is done by measuring the elements [blank] and [blank] present on the hands.

barium/antimony

T/F : Fringes with all types of ammunition can be detected by hand swabbings with nitric acid.

False

Microscopic primer and gunpowder particles on the adhesives applied to a suspected shooter's hand can be found with a [blank].

scanning detection

T/F : Restoration of serial numbers is possible because in the stamped zone the metal is placed under a permanent strain that extends beneath the original numbers.

True

T/F : It is proper to insert a pencil into the barrel when picking up a crime-scene gun.

False

Recovered bullets are initially on either the [blank] or [blank] of the bullet.

base/nose

T/F : Because minute traces of evidence such as paint and fibers may be adhering to a recovered bullet, the investigator must take care to remove these trace materials immediately.

False

T/F : Cartridge cases are best marked at the base of the shell.

False

The clothing of the victim of a shooting must be handled so as to prevent disruption of [blank] around bullet holes.

gunpowder residue

A [blank] is any impression caused by a tool coming into contact with another object.

tool mark

Tool marks compare only when a sufficient number of [blank] match between the evidence and test markings.

striations

Objects bearing tool marks should be submitted intact to the crime lab or a [blank] should be taken of the tool mark.

cast

An imprint may be lifted using lifting sheets or a [blank].

electrostatic lifting device

Shoe and tire marks impressed into soft earth at a crime scene are best preserved by [blank] and [blank].

photography/casting

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

individual