Criminalistics part 3,5

18問 • 3年前

問題一覧

_________ is a pyrotechnic composition, an explosive mixture of sulfur, charcoal and potassium nitrate, it is also known as saltpeter that burns rapidly, producing volumes of hot solids and gases which can be used as a propellant in firearms and fireworks.

Gunpowder

The term ___________ was coined in the late 19th century, primarily in the United States, to distinguish prior gunpowder formulations from the new smokeless powders and semi- smokeless powders, in cases where these are not referred to as cordite.

black powder

__________ featured bulk volume properties that approximated black powder, but had significantly reduced amounts of smoke and combustion products.

Smokeless powders

. It is cited as composed of 79% nitrate, 3% sulphur, and 18% charcoal per 100 of dry powder, with about 2% moisture. These __________reduced burning rate even further by using as little as 2 percent sulfur and using charcoal made from rye straw that had not been completely charred, hence the brown color.

Brown Gunpowder

It was a product developed by DuPont in 1911 one of several semi-smokeless products in the industry containing a mixture of black and nitrocellulose powder.

Lesmok Gunpowder

They typically contain 70.5 parts of saltpeter and 29.5 parts of charcoal. In United Kingdom, the finest grain was known as sulfur-free meal powder _________Coarse grains were numbered as sulfur-free gunpowder: “SFG 12,” “SFG 20,” “SFG 40,” and “SFG 90,”

Sulfur-Free Gunpowder

(1629-1695) experimented with gunpowder in 1673 in an early attempt to build an internal combustion engine, but he did not succeed.

Christian Huygens

The ________ is the direction of the striations left by the barrel’s rifling. Clockwise, or right-handed or counter-clockwise, or left-handed.

twist

are the identified rifling pattern, that is, 8/right and the diameters of the individual lands and grooves.

General rifling characteristics or GRC

It is performed first on the exhibit because it will not interfere with later tests for lead residues, and to detect the presence of nitrite residues.

Modified Griess Test (MGT)

Are impressions that are produced by a tool or instrument on a receptive Surface. In the world of forensic ballistics, tool-marks can take the form Of a negative impression or an abrasion mark or striations.

Tool-marks

appear when a bullet is fired through a rifled barrel the raised and lowered spirals of the rifling

Striations

are used to determine basic class characteristics of fired bullets, bullet fragments and cartridge or shot-shell cases

Stereo microscopes

uses sophisticated electronic and optical technology to digitally compare evidence stored in the database. provides a single system capable of comparing both types of ballistic evidence found at crime scenes

The Integrated Ballistic Identification System (IBIS)

are 2D or 3D tool-marks and therefore, must be geometrical surface topographies by nature.

Ballistics signatures

it is to be made on the unique surface contours,” and surface contour patterns comprised of individual peaks, ridges and furrows; specifically, the relative height or depth, width, and curvature.

comparison of tool-marks

are used for the identification of an individual firearm, and to connect the fired bullets or ejected cartridge cases to a firearm, a criminal act and a suspect.

individual characteristics

are geometrical micro-topographies, direct measurement and correlation of the surface topographies can avoid the effect of lighting conditions, and likely improve the correlation accuracy for ballistics identification, such as firearms, bullets, and cartridge cases.

Ballistics signatures

Lea set A

Christian Jay Santos · 53問 · 3年前

Lea set A