Unit 8 - Arson, Explosives, Document Analysis

Final Exam

Arson

Criminal act of intentionally setting fire without lawful consent (was there a motive?)

Activation energy

Energy given to get a reaction going

Catalyst

Compound that lowers activation energy of reaction, increasing its rate

What are hints of arson?

Many points of origin, accelerates, unusual burn patterns, color of smoke

Handheld hydrocarbon detectors

Used for screening fire scene for presence of accelerants

How to collect/preserve fire evidence

Must collect evidence fast because fire evidence is short-lived, careful documentation and photography, search warrant needed, chain of custody, evidence placed in air tight metal containers.

Physical explosives

Fast release of gas from highly pressurized containers (Kinetic energy)

Chemical explosives

Releases both kinetic and thermal energy

Primary explosives

Sensitive to heat, flames, shock, friction

Secondary explosives

Stable to heat, shock, electrical discharge

How explosives cause damage

Shock waves, heat, flying debris

Analysis of explosive evidence

GC/MS, Infrared, Resonance Ramanm Terahertz spectroscopy

Forgery

Act of altering a document with intention to damage it

Questioned document

A document that has legal dispute

Handwriting analysis

Finds information about unknown author or compare with known source to find it

Handwriting styles

Block- All caps

Script- Upper and lowercase, not joined

Cursive- letters joined

Limitations to handwriting analysis

Questioned or exemplar documents are too short to show common variations a person may possess in writing

Different techniques of forgery

Freehand, traced, traced impression