fire investigations

Question 1

what is the name of the resource for fire and explosion investigations?

Answer 1

NFPA 921, Guide for fire and explosion investigations

Question 2

what does the NFPA 921 provide?

Answer 2

incident origin, cause, responsibility, prevention, and the damage and injuries that arise in such cases

Question 3

what are the fire investigation guidelines?

Answer 3

• using scientific method in origin and cause investigations
• documenting so all relavant facts are gathered for future use in court
• handling fire-related evidence so its admissible in court
• understanding many of the terms related to fire investigations

Question 4

what is the scientific method for fires and explosions?

Answer 4

1. recognize the need (identify the problem
2. define the problem
3. collect data
4. analyze the data
5. develop a hypothesis
6. test the hypothesis
7. select final hypothesis

Question 5

T/F: you can only make and test on hypothesis when investigating fires.

Answer 5

false, you can make as many as needed and go back and forth

Question 6

T/F: you can immediately select a final hypothesis after developing it

Answer 6

false, you must test before

Question 7

Where are potential ignition sitess most likely to occur?

Answer 7

proximal to the area of origin

Question 8

what does the ignition sequence mean?

Answer 8

factors that allow the ignition source fuel, and oxidant to react, thereby causing the fire

Question 9

T/F: the oxidant for most fires is the available air in the atmosphere.

Answer 9

true

Question 10

what are questions needed to be asked during fire investigations?

Answer 10

1. is the ignition source competent to ignite the fuel
2. is the ignition source close enough to the fuel to ignite it?
3. is there evidence of ignition?
4. is there a pathway for a fire ignited in the first fuel to ignite the main fuel

Question 11

for the fire case study, what was the first fuel to ignite?

Answer 11

oil

Question 12

What was the next fuel source in the kitchen fire study? Why?

Answer 12

the cabinet and its contents above the stove, this was because the oil was hot and had a pathway to get to the cabinets

Question 13

what was the hypothesis of the kitchen fire study?

Answer 13

the fire resulted from an unattended pot of oil on a hot element on the stovetop

Question 14

what is effected in fire investigations in the extreme cold? What needs to be considered?

Answer 14

everything, including the basic equipment. Clothing, transportation, and logistics need to be carefully considered

Question 15

At ____ everything can be encased in ice with a thickness of anywhere between ___ and ____

Answer 15

-40 degrees celcius. and between 5-30cm

Question 16

what is a unique struggle of extreme cold?

Answer 16

difficulty in accessing the structure which may present safety hazards (slip and fall risks, structural collapse, and falling ice)

Question 17

When is ignitable liquid residues relavent?

Answer 17

in almost all arson cases and since the type of accelerant is consequently very useful to know for investigators

Question 18

in many arson cases what is most commonly used to initiate or accelerate a fire?

Answer 18

ignitable liquids

Question 19

What is the minor prescence in gasoline?

Answer 19

naphthenes

Question 20

what is present and predominant in gasoline?

Answer 20

aromatics, indanes, and fused aromatic rings

Question 21

what is in distillates?

Answer 21

alkanes, aromatics, indanes, napthenes and fused aromatic rings

Question 22

In Isoparaffinic products what is/isn’t present, what is the major/minor composites?

Answer 22

is: alkanes, and naphthenes
isn’t: aromatics, indanes, fused aromatic rings
major: alkanes
minor: naphthenes

Question 23

Aromatic products include:

Answer 23

aromatics, indanes, and fused aromatic rings

Question 24

naphthenic/paraffinic products include:

Answer 24

alkanes, and naphthenes

Question 25

n-alkane products include:

Answer 25

alkanes, and naphthenes

Question 26

De-aromatized distallates include:

Answer 26

alkanes, and naphthenes

Question 27

what are two ways of melting ice in extreme cold cases?

Answer 27

salamander heaters, or warm water hoses for thawing frozen debris

Question 28

what are common laboratory practices for ignitable liquid residues?

Answer 28

headspace/adsorption technique to sample volatiles from debris container

Question 29

T/F: liquid ILR samples can also be tested.

Answer 29

true

Question 30

How should ILRs be submitted to the laboratory?

Answer 30

in metal cans so they will not evaporate

Question 31

What is the way to test for ILRs?

Answer 31

gas chromatography-mass spectrometry is used most widely for the determination of accelerants in fire debris

Question 32

who sets out the guidlines for identification and classification of ILRs? by what?

Answer 32

American Society for Testing and Materials International (ASTM international) by GC-MS

Question 33

who maintains the fire database? what is included in it?

Answer 33

National Center for Forensic Science, it includes ILR identifications, and classifications from fire debris by GC-MS

Question 34

T/F: GC-MS is an advantageous tool for emergency first-responders

Answer 34

true

Question 35

what does the cross contamination study look into?

Answer 35

if the specific bag/container helps prevent cross contamination of gasoline

Question 36

did NBH that was heat sealed have cross contamination

Answer 36

yes, some

Question 37

which was better the can in the nylon bag or the heat-sealed nylon bag?

Answer 37

the can in the nylon bag

Question 38

which type of containers had a lot of gasoline cross contamination?

Answer 38

can with commercially available ring, and the can in double layer commercial evidence bag.

Question 39

what fire debris databases exist?

Answer 39

- various ignitable liquids - various surfaces - pre and post fire surfaces

Question 40

T/F: there is an international database on ignitable liquids.

Answer 40

true

Question 41

what are possible background interferants?

Answer 41

- toluene/xylenes, - medium petrolieum distallates and heavy petroleum distallates, -isoparaffins (alkanes) - normal paraffins (unbranched) - alcohols, and acetone

Question 42

can DNA analysis be done on evidence after it has been exposed to fire?

Answer 42

yes, it can be detected after being exposed ot heat and fire within limitation though not above 800 C for extended periods of time.

Question 43

can we test for fingerprints after a fire?

Answer 43

yes it is still possible

Question 44

at what percentage was print recovery found at 300C?

Answer 44

92% print recovery

Question 45

at what percentage was print recovery found at 450C?

Answer 45

6% print recovery

Question 46

at what percentage was print recovery found at 600C?

Answer 46

~0%

Question 47

in the cremation oven expirement, what is the minimum recovery rate of all powders at 300C?

Answer 47

~80%

Question 48

regarding R. v. Mac what happened, generally.

Answer 48

there was a fire started in the front drivers area of the passenger compartment of the van

Question 49

at 450C in a cremation oven what is the average recovery rate of fingerprints

Answer 49

~65%

Question 50

what two sources were found to possibly starting the fire in R. v. Mac?

Answer 50

1. book of paper matches inside the vehicle 2. disposable lighter outside the vehicle

Question 51

what ignitable liquids were detected in R. v. Mac?

Answer 51

gasoline, acetone, and isopropanol

Question 52

where was gasoline identified on, in R. v. Mac?

Answer 52

1. burnt carpet sample, 2. clothing under the bodies, 3. floor mat from the van, 4. soil under the east side of the van, 5. and clothing