Forensic Science: Glass Evidence

These flashcards cover key concepts related to glass evidence in forensic science.

Glass

A hard, amorphous, and brittle material made by melting silica, calcium oxide, and sodium oxide at high temperatures.

Amorphous

Lacking a definite shape or form.

Laminated Glass

Two or more panes of glass bonded by a plastic middle layer.

Tempered Glass

Glass subjected to extreme temperatures or chemical treatments to improve its strength.

Bullet-resistant Glass

Laminated and tempered glass composed of two layers, one hard and one soft.

Refractive Index

A measure of how much light bends as it travels through a material.

Becke Lines

Halo-like rings that appear around a glass fragment submerged in a liquid with a different refractive index.

Radial Fractures

Fracture lines that start at the point of impact and move outward.

Concentric Fractures

Fracture lines that form circles around the point of impact.

Density Calculation

Density is calculated by dividing mass by volume, typically in grams and mL.

Heat Fractures

Wavy fracture lines that develop on glass exposed to high heat.

Backscatter

Glass fragments left on the side of the impact during an event.

Submersion Method

A technique used to estimate the refractive index of a glass sample.

High-velocity Impact

An impact that results in a greater number of concentric fractures; used to distinguish bullet holes in glass.

Glass Evidence Collection

The process of separating collected glass by physical properties including size, color, and shape/texture.