4. Fire and Explosion Investigation

Question 1

Outline steps for initial action

Answer 1

1. Briefly interview informant.
2. Secure and control scene.
3. Initial interview of specialise fire investigator and O/C of first fire appliance to arrive at scene.
4. Interview the incident controller and find out – details of initial call, state of fire when Fire Service arrived, action taken by Fire Service, info about buildings security, alterations made to the scene by Fire Service, whether fire is suspicious and why, their opinions of informant, and details of 1C people or vehicles in vicinity.
5. Once fire extinguished, ensure safety of scene, hold initial conference, and conduct preliminary scene exam.
6. If suspicious, regroup and hold briefing conference.
7. Determine plan of action. Deploy staff to guard and control scene, identify and interview witnesses, conduct local enquiries.
8. Contact Comms and request attendance of specialists.

Question 2

what are some key considerations for guarding and controlling the scene?

Answer 2

ensuring the scene is not interfered with, exclusion and control of onlookers and property owners, preserving evidence, preventing looting. Should also be aware of re-ignition of hot spots, any possible suspects.

Question 3

What must you do if you cannot preserve the scene?

Answer 3

must record the scene prior to demolition by: sketches, photos, plans, video recording.
Consideration should be given to ‘storage’ of the removed spoil.

Question 4

how should you prepare for a scene exam?

Answer 4

the scene should be examined systematically from the outside in. Establish a clear area for material removed during the search and avoid any cross contamination potential.

Question 5

What is the point of origin?

Answer 5

the exact location at which a component failed, a fire was maliciously lit or an accidental fire originated.

Question 6

What will a Specialist Fire Investigator consider in determining the seat of a fire?

Answer 6

• Witness reports
• When they first noticed the fire, and where they were at the time
• The state of the fire at the time
• The direction of the spread
• Wind direction, speed and the weather
• Direction of spread
• Colour of flames and smoke
• Severity of damage
• Depth of charring
• Presence of starting devices
• Reports and opinions from specialists

Question 7

What should you take into account in an external examination?

Answer 7

accelerant containers, attempts at forced entry, broken windows or doors; nearby alleys/driveways, yard of the fire effected property, the periphery of the structure itself, what distance debris was scattered. The structure itself may reveal: jemmy marks or signed of forced entry, window glass broken, burn patterns.

Question 8

What should you note in a preliminary internal examination?

Answer 8

areas in need of repair, signs of hardship, rifled premises, open cabinets or missing files, missing personal items, presence of accelerant containers or trails, unusual odours, or burn patterns.

Question 9

What should you note in a detailed internal examination?

Answer 9

note observations including: smoke deposits and burn patterns, spalling, damage to wall studs or roof timbers or window sills/door edges, soot deposits, floor area burned through.

Question 10

What should you look for as the cause of the fire?

Answer 10

look for evidence of accelerants e.g. containers, traces in debris, smell, uneven burning, multiple seats of fire; or evidence of intentional interference e.g. tampering with alarms/sprinklers, hindering access, removal of valuable property, signs a crime was committed

Question 11

How do you deal with exhibits?

Answer 11

1. Photograph in situ, label exhibits and preserve in containers
2. Use approved arson kits
3. Take control samples: charred timber and ashes or debris from the seat of the fire for examination and comparison with samples from other points, any accelerants found, soil from surrounding area.

Question 12

What are some ways to identify suspects?

Answer 12

circumstances of the fire, fingerprints, info from informants and witnesses, media response, info from fire crews who regularly attend fires.

Question 13

Who can be possibly suspects?

Answer 13

• Owner/occupier – insurance fraud
• Employee – cover theft or forgery
• Criminals – cover traces of crime
• Aggrieved person – revenge, jealousy, etc
• Pyromaniac

Question 14

What is different for IA for fires involving explosives?

Answer 14

1. Remember there may be a secondary device at the scene.
2. Do not use cell phones, radios or other transmitting devices.
3. Evacuate the scene to a distance of at least 100m.

Question 15

What do you look for in explosions?

Answer 15

cratering, spread of debris, shredding of materials, a smell associated to the exploded material, an overlay of dust, shrapnel marks.

Question 16

Once the preliminary internal examination is done, what should you do?

Answer 16

you should hold another conference to plan your course of action. This should be documented in a decision log. Confirm all parties agree and set timings and role. Conduct site risk assessment and safety plan.

Question 17

Explain what conferences are used for

Answer 17

these must be held during scene examination to assist with: assessing info obtained, reconstructing, establishing possible motives, identifying suspects, planning further enquiries.

Question 18

Outline the enquiry steps for fires not involving explosives

Answer 18

1. Submit articles to ESR for analysis
2. Issue an offence report
3. Obtain reports, photos and plans from the SFI
4. Plan enquiries and ensure people are interviewed
5. Consider area canvas
6. Think about motives
7. Contact insurance company and obtain details or assessor and other particulars.

Question 19

What are common electrical ignition sources?

Answer 19

• Heaters and clothing
• Electric lamps and petrol ignitors
• Fallen lamp
• Pot on the stove
• Ceiling fans
• Appliances

Question 20

How do you examine a fire scene involving explosives?

Answer 20

1. Once scene clear, conduct a scene examination. Use video and photos
2. Remember to continually reconstruct.
3. Request attendance of ESR specialist

Question 21

How does a low powered explosive operate?

Answer 21

will explode in a general manner, causing damage and spreading debris over roughly the same distance in all directions.

Question 22

How does an explosive explode at a rate of 1200-1500mps vs >5000mps.

Answer 22

1200-1500mps - characterised by damage that occurs in a ‘least line of resistance’ pattern i.e. windows, door and walls blow out.

> 1500mps - do so in a directional manner. Sometimes explode straight up and down.

Question 23

Explain difference in gas explosions vs lighter than air gases vs heavier than air gases.

Answer 23

Explosions by gas generally cover a wider area than those caused by explosives and they do not leave a crater.

Lighter than air gases, e.g. hydrogen, create an outward blow at the top of the wall.

Heavier than air gases blow out the bottom of a wall.

Question 24

What must you ensure when using a Suspicious Fire Sampling Kit?

Answer 24

• The samples have not been, and cannot be, cross contaminated
• All containers are sealed and clearly labelled
• Liquid samples are secure and isolated from other exhibits
• The kit is forwarded as a unit, even if only one container has been used
• The package is correctly addressed

Question 25

How do you package and send liquid samples?

Answer 25

do not forward liquid samples in anything other than the bottles provided. Ensure that the tops are tightly fastened. Clean the outside surface of the bottles and place the bottles in the polystyrene box. If possible hand deliver the samples or place in a tin, secure the tin and send the entire kit.