1. Arson
Chapter 7

2. Determining Where & How
Point of Origin
Most damage
V Pattern
Eyewitnesses

3. Accident vs Incendiary
Search for Accelerants and/or Ignitors
Accelerants
Almost always overused
Collect in areas that won’t burn
Discovered using an arson dog or a Vapor Trace Analyzer (VTA)

4. Tools in the Field
Arson Dog VTA

5. Ignitors Most common is a match.
The striking surface on matchboxes is typically composed of powdered glass and red phosphorus
The match head is primarily composed of potassium chlorate

6. In The Lab…
Once collected, accelerants are usually analyzed by a Gas Chromatographer – Mass Spectometer (GC-MS)
Gas Chromatographer breaks the accelerant down into its simplest chemicals
Mass Spectrometer identifies those chemicals to ID the accelerant

7. GC-MS

8. Searching for Victims Asphyxia
Normal CO levels in non-smoker are <5%
Approx. 5% in smokers
House fires can reach 45-90% CO levels
At 20% CO levels, dizziness & confusion
At 35% CO levels, weakness & loss of coordination
At 50%+ CO levels, loss of consciousness or death

9. Searching for Victims Most bodies aren’t cremated in a house fire.
House fires only reach about 500-2,000oF and are put out in less than an hour from starting
Cremating a body requires 1,500oF for 2 hours

10. Searching for Victims
The medical examiner will look for two things to identify death by asphyxiation
1. Soot in mouth, throat, and lungs
2. Carboxyhemoglobin
The CO will bind to hemoglobin in blood.
Blood, organs, and muscles will turn bright red as a result.

11. Carboxyhemoglobin