Forensics

Ballistics

The scientific study of the motion, behavior, and effects of projectiles, especially bullets, bombs, and rockets.

Significance of Ballistics in Forensic Science

Helps determine the type of firearm used, link bullets and cartridge cases to specific weapons, assists in reconstructing shooting incidents, and supports criminal investigations with objective evidence.

Internal Ballistics

The study of projectile behavior within the firearm from trigger pull to bullet exit.

External Ballistics

Analysis of the bullet’s flight path after it exits the barrel until it hits the target.

Terminal Ballistics

The study of what happens when the projectile hits the target.

Handguns

Small firearms that can be semi-automatic or revolvers, easy to hide and manipulate.

Rifles

Long-barreled guns designed for precision, fired from the shoulder with rifled barrels for accuracy.

Shotguns

Firearms that use shells loaded with pellets or slugs, effective at close range due to smooth barrels.

Components of a Cartridge

Includes the bullet (projectile), casing/shell, gunpowder/propellant, and primer.

Gunshot Residue (GSR)

Particles of unburned powder and primer expelled during firing, found on the shooter's hands and clothing.

Class Characteristics in Ballistic Evidence

Features shared by a group of firearms, helping to narrow down possible weapons.

Individual Characteristics in Ballistic Evidence

Unique markings caused by manufacturing imperfections that link a bullet or casing to a specific firearm.

Comparison Microscopy

A technique that enables side-by-side analysis of bullet or casing striations.

Ballistic Imaging

Digital comparison technique using high-resolution images for firearms investigation.

Test Firing

The process of firing a suspect gun into a water tank or gel block to recover bullets for comparison.

NIBIN

National Integrated Ballistic Information Network, a database for storing digital images of cartridge casings.

Trajectory Analysis

Determines bullet path and shooter position using entry/exit wounds and angles of impact.

Factors Affecting Ballistic Testing Accuracy

Includes condition of evidence, contamination, environmental conditions, firearm condition, and human error.

Arson

The intentional, malicious act of setting fire to property, structures, or land.

Legal Implications of Arson

Arson is classified as a criminal offense with varying penalties depending on property value and presence of occupants.

Common Motivations Behind Arson

Include financial gain, revenge, vandalism, crime concealment, pyromania, and terrorism.

Fire Dynamics

The study of how fires start, spread, and are extinguished.

Stages of Fire Development

Includes incipient, growth, fully developed, and decay stages.

Fire Triangle

The components necessary for fire: heat, fuel, and oxygen.

Evidence Collected in Arson Investigations

Includes debris samples, accelerant residues, electrical wiring, ignition devices, and witness statements.

Burn Patterns

Patterns that help determine the point of origin and fire's progression.

Accelerants

Substances that speed up fire spread and indicate deliberate ignition in arson investigations.

Gas Chromatography-Mass Spectrometry (GC-MS)

A method used to detect trace amounts of accelerants from arson sites.

Role of Witness Interviews in Arson Cases

Witnesses may provide timelines, identify suspicious behavior, and corroborate physical evidence.

Psychological Profiling of Arsonists

Helps law enforcement understand motives and behavior of arsonists based on crime scene analysis.