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Flashcards in Explosives Deck (27)
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1
Q

Initial response for explosion incident is:

A
  • Gain control of the scene
    Preservation of life and treatment of casualties first priority
    Identify victims
    Important to have forensic awareness training
2
Q

Post explosion incident scene control:

A
  • Gain control of scene
  • Place cordon around scene, radius of 100-200m
  • Point of explosion would be the center point
  • Radius will depend on debris field and environment
3
Q

Purpose of Cordon is:

A
  • Preserve the scene
  • Allows systematic and effective recovery of evidence
  • Control access and movement
  • Allow forensic recovery to happen in undisturbed and safe way
4
Q

Goals for recovery after explosive incident is:

A
  • Determine cause of explosion
  • Construction, components and functioning of explosive device
  • Nature of explosive charge
  • Recover physical and chemical evidence
5
Q

Place recovered items from explosion in airtight nylon bag:

A
  • Time and date of recovery
  • Recovery location
  • ID of person recovering evidence
  • Unique identifier
  • Log item out of scene
6
Q

Two essential components of explosive device:

A
  • Explosive charge

- Means to initiate charge

7
Q

Parts of explosive device may include:

A
  • Explosive train/ various explosives to achieve detonation
  • Electrical components/ wires, batteries, leds
  • Timing devices
  • Shrapnel/ nails and screws
  • Sensors/ proximity and movement
  • Switches/ mechanical and electronic
8
Q

Types of explosions:

A
  • Mechanical/ buildup of pressure until vessel fails
  • Chemical/ chemical reaction from heat, light gases
  • Nuclear/ splitting or fusing of atoms; energy from heat and X-rays
  • Electrical/ high energy arcs that generate heat for explosion;energy of
    reaction energizes atoms of target material until breakdown occur
    Ex: lighting, short circuit
9
Q

Primary effect of explosion:

A
  • Blast wave (pressure)
  • Fragmentation
  • Incendiary (thermal component)
10
Q

Blast wave is:

A
  • Pressure wave that radiates outward from point of explosion
  • May be produced by expanding gases and combustion
  • Causes the most damage
  • Radiates outward rapidly; distance increases, speed and pressure drop
  • At point of explosion, vacuum created air is pushed away by pressure
    wave
11
Q

Fragmentation is:

A
  • Device broken into pieces by blast or when objects are attached
    to the outside or included inside a device to increase blast
    damage to kill and injure personnel
  • Common in IEDs and hand grenades
  • Low explosives (cause large rectangular shaped fragments)
  • High explosives ( cause small triangular shaped fragments)
12
Q

Fragmentation types are:

A
  • Primary (shrapnel or fragments from initial explosion)
  • Device casing or objects attached to outside

Secondary (when primary fragments stroke something and impart directional energy to that object)

13
Q

Primary effect of explosion:

A

Incendiary Thermal Effect

  • High temperature from explosion
  • Maybe localized at point of explosion
  • Can be done remotely from hot fragments hurled outward from point of explosion
  • Most incendiary explosions will cause incendiary effect of some type
14
Q

Improvised Explosive Device (IED) consist of:

A
  • Detonator
  • Booster
  • Main Charge
15
Q

Elements of IEDs:

A
  • Explosive
  • Initiation System
  • Container
  • Binding material
  • Shrapnel and other hazardous material
16
Q

IED components are:

A
  • Switch
  • Initiator
  • Explosive
  • Power source
17
Q

Essential components of explosive device:

A
  • Explosive charge
  • Means of initiating charge
  • Post explosion; basis of forensic recovery.
18
Q

Four major elements of explosion:

A
  • Rapid increase in gas pressure
  • Confinement of pressure
  • Rapid release of that pressure
  • Damage or change to the confining structure of the vessel
19
Q

Post explosion recovery:

A
  • High explosive (shattering ability, damage such as irregular fracture provide evidence of detonating explosive; plastic melting and microscopic cratering
  • Deflagrating explosives (recovered post explosion in unreacted state; like propellants in pipe bombs; rupture of vessel lead to quenching of reaction resulting in unconsumed explosive charge available for recovery.
20
Q

Recovery of evidence from bodies:

A
  • Types of injuries received by victims
  • Shrapnel (fragments from explosive device may identify it)
  • Victims should be examined and X rayed locate, recover and ID source
  • Chemical examinations may ID explosive device
21
Q

Results of explosion:

A
  • Structural damage
  • Broken gas lines
  • Broken water lines
  • Downed electrical lines
  • Release/ production of toxic materials
  • Biological issues
22
Q

Primary blast injuries known as PBIs:

A
  • Caused by large pressure differential of blast wave
    shearing, implosion and acceleration/deceleration injuries
  • Hollow medium filled tissues such as ears, lungs and GI at higher risk
    then solid organs
  • Total body disruption (TBD); amputation
  • Usually occur to victims in close proximity(suicide bombers)
23
Q

Secondary blast injury (SBI):

A
  • Caused by objects accelerated by explosion
  • Velocity (injury potential of projectiles based on magnitude)
  • Weight of projectile, distance from source of explosion
  • IEDs employ additives such as screws and nails for similar effect
  • Account for majority of injuries in survivors
24
Q

Modes of activation:

A
  • Delay activation
  • Victim activation
  • Command activation
25
Q

An explosion is:

A

A rapid expansion of gases resulting from a chemical or physical action that produces a pressure wave.

26
Q

Tertiary Blast injury (TBI) is:

A
  • Result of displacement of victim by blast wind.
  • Victim propelled along ground, resulting in contusive blunt trauma
  • Victim launched through air; may collide with stationary objects.
  • Severity of TBI depend on proximity and magnitude of blast.
27
Q

Quaternary Blast injury :

A

Result from variety of blast effects
- Burns, chemical and toxic dust poisoning, radiation exposure,
crush injury due to building collapse