Chapter 14

Question 1

All fires and explosions should be investigated to determine their origin and cause.

Answer 1

14

Question 2

A fire investigation normally ends if it is determined that an accident or an act of nature caused an incident, or if there was no loss of life or high content loss.

Answer 2

14

Question 3

It is the CO’s and IC’s responsibility to ensure that potential evidence is not disturbed or destroyed during suppression operations, if possible.

Answer 3

14

Question 4

The overhaul process should be delayed until the cause of the fire has been determined and any evidence protected.

Answer 4

14

Question 5

When it is necessary to move the evidence, first responders should record the time and the name of the person moving the evidence.

Answer 5

14

Question 6

Photograph the evidence in place, take close ups as necessary, and note the location on the fire scene sketch.

Answer 6

14

Question 7

Once a company officer handles or collects evidence, he or she then becomes a link in the custody chain.

Answer 7

14

Question 8

Maintaining the chain of custody of evidence is essential if it is to be admitted into evidence during a trial.

Answer 8

14

Question 9

Once an item is considered evidence, it should be properly secured, and its handling and transfer of custody should be documented from discovery until it reaches its final disposition.

Answer 9

14

Question 10

Chain of custody issues extend beyond physical evidence collected at a fire scene.

Answer 10

14

Question 11

All incident related evidence including documents of evidentiary value, and any other items that support the findings of the investigation are also subject to chain of custody rules.

Answer 11

14

Question 12

The chain of custody documents the chronological history and integrity of the evidence.

Answer 12

14

Question 13

Good documentation is essential in any investigation because most scenes are altered or destroyed during or after an investigation.

Answer 13

14

Question 14

Photographs should be taken as soon as possible, even during fire suppression activities if possible.

Answer 14

14

Question 15

Do not use personal smartphones to take pictures of potential crime scenes.

Answer 15

14

Question 16

The area of origin is that area where the ignition source and material first ignited actually came together.

Answer 16

14

Question 17

Fire or explosion origin and cause investigations may be complex and may require a high degree of technical expertise.

Answer 17

14

Question 18

A systematic approach is needed to evaluate the scene.

Answer 18

14

Question 19

The data gathered during the systematic evaluation of the fire scene is analyzed using the scientific method.

Answer 19

14

Question 20

If the cause is not apparent, CO’s should contact an investigator who will use a methodology that typically involves working from the least damaged area to the most damaged area.

Answer 20

14

Question 21

The scientific method provides a systematic evaluation of the fire scene.

Answer 21

14

Question 22

Identifying witnesses, securing the scene, and noting initial scene observations are critical to the success of the investigative process.

Answer 22

14

Question 23

Observing fire effects and recognizing and interpreting fire patterns will help CO’s determine where the fire originated and how it spread.

Answer 23

14

Question 24

The investigation of a structure fire should start with an examination of the entire incident scene in order to determine its size and scope.

Answer 24

14

Question 25

Fire and products of combustion, fire suppression efforts, and venting from the interior of the building or ignition points on the outside can cause exterior fire damage.

Answer 25

14

Question 26

During the exterior examination, note any fire and ventilation patterns.

Answer 26

14

Question 27

The patterns found during the interior examination represent the history of the fire from ignition to extinguishment.

Answer 27

14

Question 28

Part of fire pattern analysis is determining the order in which the patterns were created.

Answer 28

14

Question 29

The goal of analyzing fire patterns is to determine fire spread from the area of origin.

Answer 29

14

Question 30

Fire patterns also provide information about how the fire traveled within the building and about the fuels involved during the progression of the fire.

Answer 30

14

Question 31

NFPA 921 Guide for fire and explosion investigations, describes fire patterns as the visible or measurable physical effects that remain after a fire.

Answer 31

14

Question 32

Fire patterns are formed on interior surfaces of a structure as a result of direct flame contact or exposure to heat.

Answer 32

14

Question 33

Conduction, convection, or radiation can be the heat transfer method that causes a fire pattern.

Answer 33

14

Question 34

Typically, fire patterns have visible boundaries or borders where the fire or products of combustion affected a surface, leaving adjacent surfaces less affected or intact.

Answer 34

14

Question 35

When examining fire patterns, company officers should consider the time it developed.

Answer 35

14

Question 36

Should the room or area reach full involvement, the V-shaped pattern that the plume above the initial fuel creates could be obscured or unrecognizable.

Answer 36

14

Question 37

Fire patterns provide information about the fires that cause them.

Answer 37

14

Question 38

When exposed to less energy from the fire, the damage to combustible surfaces may only cause charring or discoloration.

Answer 38

14

Question 39

The physical characteristics of a surface can also affect the type of pattern found.

Answer 39

14

Question 40

The increased surface area and turbulence created as fire gases flow over rough surfaces result in additional damage.

Answer 40

14

Question 41

When exposed to extreme heat, concrete may spall.

Answer 41

14

Question 42

Plume generated - Fire pattern created as a result of the plume of hot gases rising above an individual fire.

Answer 42

14

Question 43

Hot gas layer - Fire pattern that radiant heat forms in the hot gas layer during a fire before flashover. These patterns are found when fires are extinguished before the fire has reached flashover.

Answer 43

14

Question 44

Ventilation generated - Fire pattern that can vary widely in appearance, created by ventilation introduced to a fire.

Answer 44

14

Question 45

Suppression generated - Fire pattern left as a result of the way the fire was extinguished during fire suppression efforts.

Answer 45

14

Question 46

Full room involvement - Fire pattern that occurs after flashover or after a fire has burned for long periods of time, in which almost all vertical and horizontal surfaces in the compartment will show signs of damage.

Answer 46

14

Question 47

Clean burns - Fire pattern found on noncombustible surfaces where there has been direct contact with or intense radiant heat on the surface. The direct flame contact burns away any accumulated soot or smoke deposits on the surface, leaving demarcation lines.

Answer 47

14

Question 48

Pointers or arrows - Fire pattern created when structural components, such as wood studs or trim are exposed to flame.

Answer 48

14

Question 49

Irregular patterns on floors - Pattern with no common shape in which the fire followed the path of available fuels.

Answer 49

14

Question 50

Saddle burns - Saddle shaped fire pattern that is the result of fire burning downward through the floor surface above the joist.

Answer 50

14

Question 51

Protected areas - Undamaged surface within an otherwise fire damaged area, possibly resulting from objects shielding the surface from the effects of the fire, generally used to refer the fire investigator to where large objects were positioned before the fire.

Answer 51

14

Question 52

The fire effects and patterns represent pieces of evidence at a fire scene.

Answer 52

14

Question 53

The history of the fire is told via a combination of the measurable and visible damage from the fire with the patterns created from the various heat sources invovled.

Answer 53

14

Question 54

The area of origin is a hypothesis that needs to be tested.

Answer 54

14

Question 55

Fires often originate near the place of heaviest damage.

Answer 55

14

Question 56

The CO must develop a hypothesis for each scenario and then test those hypotheses.

Answer 56

14

Question 57

Understanding how each pattern was generated and, if possible, the sequence, is integral to reconstructing the history of the fire.

Answer 57

14

Question 58

The CO should be able to account for the different fuel packages and the effects of ventilation to make the correct judgement about the fire’s movement and spread.

Answer 58

14

Question 59

From its point of origin, a wildland fire burns outward in all directions.

Answer 59

14

Question 60

On flat ground with consistent fuel bed and no wind, a fire would burn equally in all directions and the point of origin would be in the center of the circular burn pattern.

Answer 60

14

Question 61

In reality, wind, topography, aspect, and fuel variations affect the fire’s spread rate and direction of travel.

Answer 61

14

Question 62

White ash is a product of more complete combustion, and it appears on the exposed sides of the remaining debris.

Answer 62

14

Question 63

After evaluating scene safety and locating the area point of origin and protecting evidence, company officers may be required to determine the specific cause of the fire.

Answer 63

14

Question 64

If the CO cannot determine the specific cause or if the fire appears to be the result of a malicious or negligent act, an agency-authorized fire investigator should be called.

Answer 64

14

Question 65

Once the origin is identified, the investigator should look for heat sources that may be potential sources of ignition.

Answer 65

14

Question 66

A competent ignition source must have the three following qualities: Sufficient temp to ignite the first material, Sufficient heat energy transfer to result in the ignition of the first material, sufficient time to transfer the required heat to the first material.

Answer 66

14

Question 67

The potential ignition source should be documented, preserved, and protected if the fire appears to be the result of a malicious or negligent act or the cause is under question.

Answer 67

14

Question 68

A key component in making a fire cause determination is identifying the material first ignited.

Answer 68

14

Question 69

The ignition sequence is the sequence of events that allows an ignition source to ignite a fuel package.

Answer 69

14

Question 70

To determine the ignition sequence, it is important to develop a series of hypotheses and ask questions and gather information to test each one.

Answer 70

14

Question 71

When evaluating ignition sequences, investigators may need to consider whether someone’s action or omission was one of the events that brought together the competent ignition source with the first material ignited.

Answer 71

14

Question 72

Actions and failures to act may greatly affect the ignition sequence.

Answer 72

14

Question 73

At the conclusion of an investigation, the CO will typically determine a classification.

Answer 73

14

Question 74

Accidental - Fires that do not involve a deliberate human act to ignite or spread the fire into an area where fire should not be.

Answer 74

14

Question 75

Natural - Fires, such as those that lightning, storms, or floods cause, where human intervention has not been involved in the ignition process.

Answer 75

14

Question 76

Incendiary - A fire deliberately set under circumstances in which the responsible party knows that the fire should not be ignited.

Answer 76

14

Question 77

Undetermined - this classification is used when the specific cause has not been determined to a reasonable degree of probability.

Answer 77

14

Question 78

Once the area of origin, the heat source, and the material first ignited have been determined, the officer must select the correct fire cause classification.

Answer 78

14

Question 79

If the origin and cause are easily determined, the analysis phase of the fire investigation can be completed during the scene examination.

Answer 79

14

Question 80

Incendiary fires are those fires that are deliberately set with malicious intent.

Answer 80

14

Question 81

Collected ignitable evidence foreign to a particular location is a possible indicator of an incendiary fire.

Answer 81

14

Question 82

Irregular floor patterns can be created by many factors other than ignitable liquids, including carpet, furniture, ventilation, and concentrated fuel loads.

Answer 82

14

Question 83

Trailers usually leave char or burn patterns.

Answer 83

14

Question 84

Most incendiary devices leave behind some type of evidence.

Answer 84

14

Question 85

Potential evidence of ignitable liquids should be tested.

Answer 85

14

Question 86

Opportunity means a suspect was capable of setting the fire at the time and place where the fire was set or of procuring another individual to set the fire for them.

Answer 86

14

Question 87

Revenge - Fires set because of personal or professional vendetta. This category of arson fires account for fifty % of the total arson problem.

Answer 87

14

Question 88

Vandalism - Fires are usually set by two or more individuals.

Answer 88

14

Question 89

Profit (fraud) - Monetary gain is the primary motivator for this type of incendiary fire, and total destruction of property is the ultimate goal. Firesetters motivated by fraud attempt to cause the most possible damage in the least possible amount of time.

Answer 89

14

Question 90

Crime concealment - Arson used as a tool to destroy evidence of another crime is most generally associated with burglary, homicide, and embezzlement.

Answer 90

14

Question 91

Excitement (vanity) - Some firesetters commit arson in order to have the private satisfaction of being the one who created a situation requiring the response of the fire service and law enforcement. Fires started for the sheer excitement of creating a fire scene provide some people with a feeling of empowerment over society.

Answer 91

14

Question 92

Pyromania - is not a motive because it is a mental state and a recognized psychological disorder. True pyro’s are few and set fires to release tension or to produce euphoria.

Answer 92

14

Question 93

Extremism (terrorism) - An individual or group of protesters may target a government, an ethnic or religious group, or a facility that operates in opposition to their cause. Fires or explosions are carried out with the intent to advertise or advance the arsonist’s purpose.

Answer 93

14

Question 94

Aspect - Position facing a particular direction, exposure, compass direction toward which a slope faces.

Answer 94

14

Question 95

Ignition sequence - history of the fire, beginning when the ignition source and the first fuel ignited meet at the area of origin, and proceeding through the entire duration of fire spread through the scene.

Answer 95

14

Question 96

Ignition source - Mechanism or initial energy source employed to initiate combustion, such as a spark that provides a means for the initiation of self sustained combustion.

Answer 96

14

Question 97

Material first ignited - fuel that is first set on fire by the heat of ignition.

Answer 97

14

Question 98

Scientific method - Widely accepted, systematic approach to examining evidence in order to create hypotheses and draw conclusions about phenomena at a fire or explosion scene.

Answer 98

14i