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The Burning Question:Is it Arson?
How can we make fire?
• Heat + Fuel + Oxygen
How can we make fire?
• Oxidation: combination of oxygen with other substances to produce new substances
• Combustion: oxidation reaction with the rapid combination of oxygen with another substance accompanied by the production of heat and light
How can we make fire?
• Flash Point: Lowest temperature at which a liquid gives off sufficient vapor to form a mixture with air that will support combustion (gasoline -50oF)
How can we make fire?
• Ignition Temperature: The high temperature that is required to “jump start” the reaction between oxygen and a reactant (gasoline 495of)
Was it arson?
• Fires can be caused: • Naturally• Accidentally• Intentionally
Was it arson?
• Suspect arson if you find:• Accelerants
• Paper, black powder, kindling wood, gasoline, kerosene, alcohols, paint thinners, natural gas, propane, lighter fluid
• Incendiary Devices• Timing devices, initiators, candles,
electronic timers
What is arson?
• Sniffer/Arson Dogs• Chemical Detectors (Vapor Trace
Analyzer-VTA) screens air for accelerant residues
Where did the fire start?
• Find the point of origin (POO)• Fire spreads upward and sideways
from the POO• V-pattern
Where did the fire start?• POO has the most damage• Location of igniters and
accelerants• Stairwells & Drafts may pull the
fire in one direction• Smoke detector• Doors & Floors
Where did the fire start?
How is arson evidence collected & packaged?• Package ASAP in nonporous,
sealed containers (clean paint cans, glass jars)• Effect of water on evidence
• Collect samples from area of fire and from unburned areas to compare
• Collect suspect’s clothing
What do we do with arson evidence?
• Extract any possible accelerants from debris
• Ultra Violet (UV) Spectroscopy• Gas Chromatography (GC) - Mass
Spectroscopy (MS)• Infrared Spectrophotometry (IR)
UV Spec
GC-MS Spec
IR Spec for Gasoline
Can we tell when the victim died?• Position body was in
• Burning corpse assumes boxer’s position • Carbon monoxide levels in blood and
tissue• Asphyxia (suffocation) from inhaling smoke
and carbon monoxide (CO) • CO Intoxication – excessive CO in the
bloodstream• Toxicity of CO may prevent victim from escaping
even if there is enough time• Bright cherry red blood
• Soot in the mouth, throat, lungs, and airways
Why arson?
• Covering their tracks • Insurance fraud• Psychological reasons• Revenge• Suicide or murder• Terrorism
Arson Statistics
• The US has the highest rate of arson in the world
• One of the fastest growing crimes• $1.5 billion in property loss/year• 55% of all arson arrests are
children under 18 yoa
Arson Statistics
• Leading cause of fires• 50% of arson cases occur
outdoors, 30% in structures, 20% in vehicles
• Cooking fires are the leading cause of fire-related injury, and smoking fires are the leading cause of fire deaths
Arson & The Law
• Felony Arson – Up to $25,000 fine &/or 3-7 years in jail
• Aggravated Arson (Felony) - Up to $25,000 fine &/or 6-30 years in jail
• Residential Arson (Felony) - Up to $25,000 fine &/or 4-15 years in jail
Who are arsonistis?
• Gender• Race• Age• # Fires set• History with law• Intelligence• Education• Psychological history
Who are arsonistis?
• Family/Relationships• Hobbies• Occupation• Post-fire activity• Ego
Who are arsonists?
• Organized• Elaborate incendiary devices, less
physical evidence, methodical
• Disorganized• Uses materials at hand, more physical
evidence is left