15 Origin And Cause Determination Flashcards
The area of origin is not readily apparent company officer should use a methodology that typically involves working from
Least damage to most damage area
The area of greatest damage should not be assumed to be
The area of origin
For basic steps in determining area of origin
Examine exterior of structure or vehicles and surrounding area.
Examine interior of structure or vehicle.
Interview witnesses and responders.
Analyze the information
During cause determination when is the safety survey conducted
During the exterior search of the building
Part of fire pattern analysis is determining the order in which
The patterns were created
The goal of analyzing fire patterns is to determine
Fire spread from the area of origin
NFPA 921 describe fire patterns as
Visible or measurable physical effects that remain after a fire
Fire patterns are formed as a result of directly in contact or exposure to heat and Are found where
On interior surfaces
Hey V shaped pattern should have been made during what fire phase
Incipient phase
Rob services are often more heavily damaged and what type of surface of the same material
Smooth surfaces because rough surfaces of greater surface area
Plume generated fire pattern
Fire patterns created as a result of plume of hot gases rising above initial fire
Radiant heat forms in the hot gas later before flashover.
Hot gas layer fire pattern
What type of fire pattern is found after the when fires are extinguished before flashover
Hot gas layer pattern
Ventilation generated fire pattern
Created by ventilation introduced to a fire, varies widely
Occurs after flashover or long burn time. Almost all vertical and horizontal surfaces are damaged
Full-grown involvement fire pattern
A fire pattern found on noncombustible surfaces were so deposits have been burned away leaving a clean demarcation
Clean Burns, fire pattern
Sharp edges of structural component burned away on the side that faces heat source.
Pointers or arrows, fire pattern
Type of fire pattern that also refers to a series of components that indicate longer duration on one end and shorter on the other
Pointers or arrows
It regular patterns on floors indicate
No common pattern, fire follow the path of available feels
Saddle Burns, fire pattern
Fire that burns down through the floor over the joist
Undamaged surface within an otherwise fire damaged area. Possibly shielded from other objects
Protected areas, fire pattern
What retells the history of the fire
Measurable visible damage, patterns created from heat sources
A fire scene shows a V shaped pattern above a candle from the drapes and frame catching fire appearing charred. The window on the opposite side is heavily charred, more so than the v side. This is likely due to
Ventilation pattern. Not point of origin.
To ensure chain of custody, each piece of evidence should have the following information recorded
It’s location
Name of discovering person
Where it was found
Time and date of acquisition
When investigating a vehicle fire, investigators should use a systematic exam using the following to determine origin
Photos
Documentation
Fire Pattern analysis
Comparative analysis of damage to other areas of vehicle.
Vehicle fires can be divided into three areas of examination
Scene around
Exterior of vehicle
Interior
When examining interior of a vehicle fire, the areas should be further divided into what compartments
Engine
Cargo
Passenger compartments
Investigators should follow a certain methodology when investigating vehicle fires, which should include the following.
Vehicle history and documentation
Scene exam
Document scene
Fire pattern analysis
Examine exterior
Examine engine cargo and passenger compartment
In hybrids, exam high voltage battery compartments
The area where the ignition source material first ignited actually came together
Area of origin
Energy source in a vehicle capable of being hot enough to ignite fuel
Competent ignition source
In vehicle origin determination a sketch should be made of the vehicle in relation to
Other objects
Documenting rest angle during a vehicle fire means documenting
The angle the car is, pitched to the left or right or down a ditch etc.
Radial fire patterns show movement on
Vehicle body panels, hood doors. Fenders. May appear to ripple
Photos should be taken of what on the car during a vehicle fire
All panels, wheels lids, bumpers, undercarriage and roof
Damage to the lower portion of the windshield indicates
Fire spread from engine compartment to passenger
Fire damage to the top of the windshield indicates
Fire spread from passenger compartment to engine compartment
Documentation of cargo compartment should include
Damage in interior Personal effects and their condition Damage to spare tire Damage to wiring Fire pattern
Photographs of each vehicle compartments should be taken how
From multiple angles of each compartment
If unaffected by topography and weather, wildfires tender to burn in what direction from origin
Outward in all directions
Aspect
Direction slope faces in wildland fires NORTH S E W
In wildland fires there may be less damage near the point of origin, true false
True
If a person being interviewed is suspected of being involved in the crime, who should be present
LE or formal investigator
A fire investigator should be called if the cause is determined or suspected of being
Malicious, negligent, or with death resulting
A competent ignition source must have three qualities
Sufficient temp to ignite
Sufficient heat transfer to ignite
Sufficient time of transfer
Material first ignited
First Fuel that combusts from the ignition source
The first material ignited should have three characteristics that parallel the ignition source
Capable of being ignited by energy of the ignition source
Close enough to ignition source for heat to transfer
Capable of absorbing and retaining head from ignition source
The following are four generally accepted classifications of fire cause
Accidental
Natural
Incendiary
Undetermined
What might be used as an interim classification of fire cause until the final outcome can be decided
Undetermined
Potential motives for fire crimes
Revenge Vandalism Profit (fraud) Crime concealment Excitement (vanity, gratification) Pyromania Extremism (terrorism)
What motive for fires starting is the largest and most common contributor or category, 50 percent
Revenge
or personal or professional, vendettas
What is often the target of revenge motives
Personal property
Accelerants are not usually used in revenge fires because
They aren’t planned in advance and are impulsive
How many people usually set vandalism fires
Two or more, typically juveniles.
If vandalism is found inside a building entry was typically made how
Forced by the vandal
Monetary gain is the primary motivator for this type of motive and total property destruction is often the goal
Profit or fraud
Holes are often made in the building in order to facilitate what during intentionally set fires
Facilitate faster fire spread
Who often set elaborate fires that require a lot of prep
Building owners
Usually fires started to cover a crime are started where
At the point of entry or exit, or where the item was taken from
Fire covering is typically started with items on hand and not flammable fluids because
They enter with intent to steal not arson
Fires to cover homicide are typically started with
Ignitable liquids
Embezzlement fires are started to destroy
A paper trail, sometimes ignitable liquid used
Fires started for excitement or vanity movies are done so that the person feels what
Empowerment over society and personal satisfaction
Examples of patterns for arson fires include
Dates and day of week Time of day Type of structure How fire is set Where fire is set
Arson who wish to be viewed as heroes may do what
Set and “discover” fires and are always present on scene may may attempt to assist in efforts
Pyromania
Psychological disorder where the sufferer has uncontrollable impulse to start fires to release tension or cause euphoria
Pyromania as properly defined, is not a motive because
It is a psychological disorder
Pyromania fires are not usually started with ignitable liquids and are typically done with what and where
Paper products in vehicles and alleys often in multiple places around the city
Most juvenile fire starters do so out of psychological conflict, revenge or attention between the ages of
8-13
Children under the age of what often experiment with fire out of curiosity
7
Juveniles between what ages are often placed in detention settings and have a long history of fire abuse
15-18
Majority of fire starters are what gener
Male and have poor social skills
