Forensics Chapter 14 & 15
Which of the following is an accidental cause of fire?
Faulty wiring
What is a Molotov cocktail?
A concoction of fuels used to start a fire
What makes investigating arson cases difficult?
Act has been planned thoroughly, the perpetrator is not on the scene, the destruction is so extensive.
The depth of wood charring is called...
Alligatoring
Willfully and maliciously setting fire to or charring property.
Arson
A mixture of potassium or sodium nitrate, charcoal, and sulfur
Black powder
It merely burns when unconfined
Black powder
When smoke from a burning house moves upward and travel outside and sinks back to the ground, it exemplifies
Convection
Created after an explosion from loose soil which also yield debris for laboratory analysis
Crater
Dogs are used in fire investigation to...
Detect hydrocarbon accelerants
The product of combustion accompanied by the creation of gases and heat at a rapid rate.
Explosion
When the temperature is high enough to burn and vaporize a liquid, we say we have reached the...
Flash point
Where would you normally find telltale signs of arson?
Floor
A fuel will only ignite if it is in what state of matter?
Gas
Which of the following is an example of conduction?
Heat from a boiling pot of water travels through metal
When a substance burns, the heat produced is called
Heat of combustion
Can detonate almost instantaneously at rates of 1,000 to 8,500 meters per second
High explosives
Produce a shattering or smashing effect
High explosives
What is pyrolysis?
Hot solid turning into gas
What does a criminalist look for in a fire scene?
Identifiable chemicals
Which of the following is an example of a glowing combustion?
Lighted cigarette
This device is used to measure the speed of ions from vaporized residue of explosives
Ion Mobility Spectrometer (IMS)
Explosives with a velocity of detonation less than 1,000 meters per second
Low explosives
Have a slow burn rate
Low explosives
Produce a propelling or throwing action, making them suitable as propellants for ammunition or sky rockets
Low explosives
X-ray machines are useful in detecting bombs from...
Luggages, packages, laptops
To prevent contamination and diffusing of explosives, specimens must be placed in
Metal cans
Fires can be produced as air rushes backwards toward the explosion's origin
Natural gas
When mixed with air in confined space and ignited, will combust
Natural gas
A house with a V-shaped pattern of burning is an explanation...
Of the origin of fire.
To start a fire, you would need...
Oxygen, fuel, heat
What is the explanation for the occurrence of spontaneous combustion?
Poor ventilation and heat buildup
Can cause chain reaction with other explosives.
Primary explosives
Easily detonated by heat, shock, friction
Primary explosives
Will detonate violently instead of burning
Primary explosives
The hear from a flame travels by
Radiation
It is important in an investigation after an explosion to
Recover any trace of detonating device
To safety search ad collect bombs from a site, what must be used?
Robots controlled by teleoperators
What is as "sniffer"?
Searches for traces of flammable liquid residues.
Examples include TNT, TATP, C-4, and emulsion explosives
Secondary explosives
Relatively insensitive to heat, shock, or friction
Secondary explosives
Used in majority of chemical and military blasting.
Secondary explosives
Will normally burn rather than detonate
Secondary explosives
Consists of nitrated cotton (nitrocellulose) or nitroglycerin and nitrocellulose
Smokeless powder
Either single or double based powder
Smokeless powder
In order to find out what accelerant or fuel have been used in arson, what should be done to gather enough evidences?
Specimens around the area that have not been burned
Streamers are used to...
Spread fire
What is ignition temperature?
Temperature needed to ignite fuel spontaneously
The search of the fire scene must focus on finding
The origin of fire
Why is it necessary to place collected specimen in metal cans or glass for identification?
To prevent leaking of accelerants
Combustible liquids are rarely consumed during a fire.
True
