Fire Ashes denote that fire was; Respect the grayest pile For
the departed creatures sake That hovered there awhile Fire exists
the first in light, And then consolidate Only the chemist can
disclose Into what carbonates. By Emily Dickenson from Poems
Slide 4
Reasons for arson 1. Financial stress -profit 2. Pure fraud
-profit 3. Third party arson-profit - eliminate competition -
Labor- management problems 4. Revenge, spite, jealousy 5. Vandalism
6. Conceal a crime 7. Pyromaniac, schizophrenics - 13.4% of
arsonists are schizophrenics 8. Hero fires 1. covering their tracks
- cover theft or murder
Slide 5
Basic Questions to Ask About the Fire Where was the point of
origin? What was the cause of the fire?
Slide 6
Conducting a fire investigation Building must be safe -->
Enter building only when you have the OK from structural engineer
Accelerants will evaporate quickly so look for these first Locate
point of origin : where fire started Collect samples of
accelerants, etc... Interview witnesses Where did you see flames
first? Was there a distinct color to the flames/smoke? ex. Gas
produces a yellow flame! white smoke Did you see any suspects near
the scene?
Slide 7
Michigan vs. Tyler 1978 Once in- firefighters may seize any
evidence in plain view No warrants needed to remain in building for
reasonable time to investigate crime Fire department must be on
scene during investigation Once leave the scene- need a warrant to
return
Slide 8
Who is interviewed after a fire? 1. Witnesses 2. Firefighters
3. Insurance personnel 4. Business associates, creditors,
competitors 5. Media 6. Medical examiner or coroner 7. Suspect 8.
Owner 9. Informant
Slide 9
Types of fires A.Accidental B.Intentional (incendiary)
C.Natural (lightening)
Slide 10
LIGHTNING STRIKE
Slide 11
Accidental causes Electrical system Appliances, equipment Gas
leaks Heating units Sunlight Matches Smoking
Slide 12
Bathroom Accident
Slide 13
Why is it pointless to burn a building to conceal a homicide?
Cremation needs 1500 F for several hours A fire burns from 500-2000
F, but doesnt last long enough to cremate the body.
Slide 14
Locating point of origin 1. Know how fire moves Sideways and up
from point of origin Affected by: stairwells chemicals in synthetic
carpet decorations stored flammables
Slide 15
Locating point of origin 2. Most damage is found near the point
of origin 3. Look for V pattern of burned material 4. Steel buckles
under extreme heat 5. Spalling (cracking and flaking) on walls and
floors indicate high heat
Slide 16
Locating point of origin 6. Charred wood may have an alligator
appearance... smaller scales near the hottest part of fire 7. Check
the time smoke detectors went off through the building 8. Look for
areas of severe burns in flooring... may indicate location of
accelerant.
Slide 17
Locating point of origin 9. Look for plants - material placed
around the ignition device to feed the flame ex. Newspapers, wood
shavings, rags 10. Look for trailer used to spread the fire - may
connect plants
Spontaneous Combustion An internal chemical reaction that
starts a fire (rare) Combustible materials in enclosed space ex.
Oil-soaked rags in small pantry
Slide 21
Matches Heads of matches have diatoms Diatoms= single celled
organisms with cells made of silica (tough component that can
survive fire) Different manufacturers use different species of
diatoms
Slide 22
Accelerant Makes the fire burn faster 1. Solids- paper, black
powder, kindling wood 2. Liquids- gas, kerosene, alcohols, paint
thinners 3. Gases- natural gas, propane
Slide 23
Collecting Samples Samples near point of origin taken for
chemical analysis May use trained dogs Place samples in airtight
container
Slide 24
Signs of accelerants Flammable liquids flow down, heat travels
up Charring on bottom of furniture, etc.. deeper than charring on
top Clean floor &rugs; pattern may appear Check baseboards,
sills: liquid runs under and chars the bottom Check corners..,
floors rarely level
Slide 25
Collecting Samples Take control samples from unburned area Test
for hydrocarbon residues in the air
Slide 26
Detection of accelerants Human olfactory sense (limitations)
Scent dogs Chemical color tests Some dyes turn red in the presence
of hydrocarbons
Slide 27
Homicidal Fires Was the victim alive when the fire started?
Determine cause and manner of death
Slide 28
Medical examiner looks at: a. Position of the body b. Carbon
monoxide levels c. Presence/absence of soot in lungs - if soot
present, the person was alive and breathing at the time of the
fire. d. Nicotine levels in urine (tells if victim was a smoker...
for smoking in bed cases)
Slide 29
Asphyxia Asphyxia = suffocation From inhaling smoke and CO
Normal Carbon monoxide level is less than 5% Slightly higher in
smokers 45-90%- asphyxiation
Slide 30
CO Levels 20% - Dizziness, confusion 35% - weakness, loss of
coordination, disorientation 50% - loss of consciousness
Slide 31
Autopsy signs of CO poisoning: CO combines with hemoglobin to
form carboxyhemoglobin (bright red) If CO level is low and no soot
in Lungs-* dead before fire
Slide 32
Fire Tetrahedron
Slide 33
Slide 34
Extinguishing fires
Slide 35
Slide 36
Slide 37
When using a fire extinguisher, always remember the mnemonic
PASS P - Pull (pull the pin that locks the handle) A - Aim (aim the
nozzle at the base of the fire) S - Squeeze (Squeeze the handle to
discharge the extinguishing agent) S - Sweep (Sweep the nozzle from
side to side, to cover the fire)