Explosions Flashcards
What to look for.
Characteristic damage cause by explosives includes…..
1) cratering
2) spread of debris
3) shredding of materials
4) smell peculiar to the exploded material (eg, smell of almonds)
5) overlay of dust
6) shrapnel marks
Explosions cause by gas generally cover a wider area than those caused by explosives and they do not leave a crater.
Lighter than air gases such as hydrogen will create an outward blow at the top of a wall whereas heavier than air gases blow out at the bottom of the wall.
Other tell tail signs include implosion of cabinets which will be obvious to the expert.
May also be medical evidence that suspect or victims have inhaled gas prior to the explosion
Containers
May find pieces of the devices container scatter a considerable distance from the centre of the explosion
Non-electrical detonators
Whether traces of the detonator remain will depend on how far it was placed into the explosive.
If well inserted - find traces of the fuse only
If not well inserted - find fragments of the detonator itself
Electrical Detonators - may find
1) Lead wire which may help identify type of detonator used. Remaining wire is called “fly wire”.
2) Neoprene plug
3) Short circuiting shunt - a small piece of plastic that is removed from the wires before they are connected into the circuit.
4) The “delay setting” tag from the lead wire
5) Fragments of the electric detonator casing (although highly unlikely).
Safety Fuses
Burning leaves most of the fuse in a limp state. Should still be able to identify the colour and manufacture.
The explosion may blow the fuse off its original path. Can find the path by looking for the scorched trail left by the fuse from the point of ignition to the explosion centre.
You may also find evidence of the igniters used to light the fuse.
Detonating Cord
Usually leaves little residual trace but the surfaces over which it was laid may be damaged.
May find cut off pieces of cord that have not detonated because they have been laid on sharp angles.
Upon excavation trailers may still be located under debris that have fallen as a result of the fire.
Igniter Cord
Often contains a thin wire and leaves a black, charred, ash like remnant.
The remnant is less substantial than that of a safety fuse.
Associated Items
May also find unused explosives wrappers and packing material
Encourage the IED Operator to……
Consider using a non-destructive method of making a device safe or one that involves the least possible destruction.
This will avoid destroying evidence such as fingerprints, tool marks, wrapping paper.
HOWEVER
Safety must outweigh the preservation of evidence.
Recored this on video.
