w5 terms (Fingerprinting, Polymers & Fibres and firearms)) Flashcards
Friction ridges
A raised portion of the epidermis that enable our hands to hold up objects; pattern of friction ridges give pattern of fingerprints
Latent prints
Fingerprint impression that is not readily visible; requires chemical visualisation
Skin graft procedure
Surgical procedure involving the transplantation of skin from one part of the body to another
Visible prints
Fingerprints that are visible to the naked eye; also called patent prints
Co-polymer
Long chain molecule made up of two or more monomers
Hair cortex
Located between the hair cuticle and hair medulla; contains most of the hair’s pigments
Hair cuticle
Outermost part of the hair shaft; formed from dead cells
Hair follicle
A sac from which the hair grows; contains the root of a hair
Hair medulla
Innermost part of the hair shaft; width and pattern is characteristic of species
Hair root
The part of a hair embedded in a hair follicle
Monomer
A molecule that forms the basic unit for polymers; can be bonded to other molecules to form a repeating chain molecule
Polymer
A long chain molecule made up of many repeating units
Proteins
Large molecules composed of one or more chains of amino acids
Stereo chemical
Difference in three dimensional structure of molecules
Ammunition
One or more loaded cartridges consisting of a primed case, propellant, and projectile
Back spatter
Blood directed backward towards the surface of the energy source
Ballistics
The study of projectile in motion
Breech loading firearms
Firearms in which the cartridge or shell is loaded into a chamber integral to the rear portion of the barrel
Bullet
The projectile
Cartridge
A unit of ammunition, made up of a cartridge case, primer, powder, and bullet
External ballistics
What happens during the flight of the bullet
Firing pin
The part of a firearm mechanism that strikes the primer of a cartridge to initiate ignition
Firing pin impression
Impression on cartridge base when struck by the firing pin
Griess Test
A chemical test for the detection of nitrites
Gun Shot Residue (GSR)
Residues from the explosion of primer and charge
Internal ballistics
What happens in the gun barrel
Lands and groove
Refer to definition of Rifling; Lands are the raised portions between the grooves in the barrel after the spiral grooves are cut to produce the rifling
Muzzle loading firearms
Firearms in which the cartridge is loaded from the front
Primer
Shock sensitive compounds that detonate when they experience a shock
Propellant
A chemical that provides energy when ignited; turns into gases and particles
Rifling
Cutting of spiral grooves inside a gun barrel; metal between the grooves is called a “Land”
Sodium Rhodizonate Test
A chemical test to detect the presence of particulate lead or lead vapour around a bullet hole
Striations
Scratch marks left on the bullet’s side by grooves
Terminal ballistics
What happens when the projectile hits the target
