1) Find out that fire is the result of -
Negligence
Due to accident
Or a Malicious act
It is important for eligibility of compensation.
2) Its importance to ascertain that what was actually burned
Dwelling
Vehicles
Public property such as school factory railway station etc.
Commercial premises.
Jungle , crop , park etc.
This determination is important for public safety.
3) For investigation purpose find the cause of fire - it is
Electrical
Mechanical
Chemical
Lightning (weather)
Auto ignition
Direct ignition
Arson - Starting a fire intending to cause destruction by an arsonist to achieve his malicious intentions. For this purpose he used matchstick , candle or a fuse code , used chemicals , heating appliances such as electric heater , used inflammable liquids such as petrol , kerosene etc , used paper , clothes , grass , cotton etc to accelerate fire .
Hazards in a fire scene or in arson investigation
Structural collapse - There is always a possibility of structural collapse as fire weaken support structures , ladders , stairways etc . Fire suppression resulted in holes or floor plates missing in walkways , hanging of steel beams occurred.
Respiratory problems - when the burned area cools , gases make their way to lower levels. Combustible materials exposed or burned given off toxic gases.
Substances - polychlorinated biphenyls (PCB) found in electrical items. When they are exposed or involved in fire , dioxin evolved and spread .
Asbestos containing materials deteriorate during fire and asbestos fibers released in to air. Chemical substances which are stable become unstable when involved in fire. After the fire set down the non-burned chemicals often present at the scene.
Color of flame - Color of smoke and flame indicate materials type being burned.
|
Material
|
Smoke
color
|
Flame
color
|
|
Paper , cotton , wood , cloth etc.
|
Gray to
brown
|
Yellow to
red
|
|
Petrol , diesel , mobile oil
|
Black
|
Yellow to white
|
|
coal tar
|
Black
|
No flame
|
|
Turpentine ,
Thinners
|
Brownish
black
|
Yellow to
red ,white
|
|
Grass , hey , dry leaves
|
White
|
Yellow
|
|
Plastics , rubber
|
Black
|
Yellow
|
|
Kerosene
|
Green
|
Yellow
|
|
Acetone
|
Brown
|
Yellow
|
|
Chlorine
|
Black
|
Yellow
|
|
Benzene
|
White to
gray
|
Yellow to white
|
Temperature of Fire - Flame color provide a idea about the temperature of fire.
|
SI
|
Flame Color
|
Temperature
|
|
1
|
Normal Red
|
400-600 C
|
|
2
|
Dark Red
|
600-800 C
|
|
3
|
Bright Cherry Red
|
800-1000 C
|
|
4
|
Orange
|
1000-1200 C
|
|
5
|
Bright Yellow
|
1200-1400 C
|
|
6
|
White
|
1400 C and above
|
Smell of burning material -
|
SI.
|
Material
|
Odor
|
|
1
|
Cotton , paper , wood , grass etc.
|
Chocking effect with peculiar odor
|
|
2
|
Petroleum products , turpentine oil , rubber items etc.
|
Burning smell
|
|
3
|
Sulfur and explosive substances
|
Suffocating odor
|
|
4
|
Oxide of nitrogen
|
Pungent odor
|
|
5
|
PVC and other polymers
|
Pungent with specific odor
|
The investigator officer found out the following information in a fire and arson investigation -
He find out the nature , time , cause and seat of fire.
Which type of material being burned and the quantity of material.
How the fire is spread and its cause.
Involvement of suspected person.
Modus operandi by the arsonist.
Loss and damage due to arson.
Any other criminal act evidence.
Is fire due to malicious act or accidentally or it is spontaneous.
Step by step investigation -
1) Arrival at fire and arson investigation - First responder at the fire scene must secure the scene and provide medical attention to the victims. It observe conditions and all other activities and provided it accurately to the investigator.
2) Evaluation of the fire scene - The investigator make a preliminary survey of the scene and must be careful not to disturb the evidence. Define scene boundaries and identify the witnesses , assess scene security. He will take visual note of evidence and documents the scene.
3) Documentation - Documentation is very necessary in a crime scene. Photography or videography of the scene is must . Prepare a detailed diagram.
4) Evidence processing - The investigator with the help of expert collect , preserve and store evidence from the scene.
5) Releasing the scene and submit the report is the last step in arson investigation.
Things to remembered during investigation -
Photographing the whole scene with smoke pattern, seat of fire extent of damage etc.
Residues or burn marks of fire initiator such as fuse cord etc found at seat of fire first photographed and then collected.
Record the smell of chemical or explosive substances found at seat of fire , if they used as fire initiator.
There is a possibility of tempering with electrical installation , use electrical engineer opinion on this.
Heating appliances often remain un-destroyed and they provided useful information about origin of fire.
Possibility of fingerprints and tool marks on fire extinguisher if found tampered.
The door window and their knobs/handles , furniture should be checked for fingerprints as the arsonist believed that these articles destroyed by the fire and not take any precautions on handling.
Possibility of tools , oil containers , matchbox , lighter etc found at crime scene.
Possibility to found Footprints , fingerprints etc are greater at the point of entry than the point of ignition.
Seat of fire is the site where the fire has been ignited. For finding the cause and origin of fire the backward theory help. Bacward theory is investigating the scene from exterior to the interior and examined from least damaged to heavily damaged areas.
For information about pre - fire position of vital objects keep the owner of the house or building or the person known to crime site.
