SUPA Forensics Arson Investigation
Pour pattern
a pattern left by the vaporization of a flammable liquid
Trailers
helps transport the fire to other parts of a room or building (ex. accelerant, rags, black powder)
2nd
1. A person is guilty of arson in the __ degree when he intentionally damages a building or vehicle 2. When another person who is not a participant in the crime is present in the building or vehicle and the defendant knows that fact
3rd
1. A person is guilty of arson in the ___ degree when he intentionally damages a building or motor vehicle 2. No person other than the defendant had a possessory or proprietary interest in the building or motor vehicle or if other persons has such interest, all of them consented to the defendant's conduct 3. The defendant's sole intent was to destroy or damage the building or vehicle 4. The defendant had no reasonable ground to believe that his conduct might endanger the life or safety of another person
1st
1. A person is guilty of arson in the ___ degree when he intentionally damages a building or motor vehicle by causing an explosion or a fire and when such explosion or fire is caused by an incendiary device propelled, or placed inside such building or motor vehicle 2. When such explosion or fire caused by an explosive causes serious physical injury to another person other than a participant 3. The explosion or fire was caused with the expectation or receipt of financial advantage 4. The defendant knows that another person who is not a participant in is present in such building
4th
1. A person is guilty of arson in the ___ degree when he recklessly damages a building or motor vehicle by intentionally starting a fire or causing an explosion. 2. No person other than the defendant had a possessory in the building or motor vehicle.
5th
A person is guilty of arson in the ____ degree when he or she intentionally damages property of another without consent of the owner by intentionally starting a fire or causing an explosion
Exothermic reaction
A reaction that releases energy in the form of heat.
high. low.
As a fire progresses, the heat created by the combustion process tends to move from a ___ temperature region to one at a ___ temperature
GCMS
a machine used to analyze evidence that separates all components of accelerants.
exigent
Collection of arson evidence is the result of a warranties search or ______ circumstances.
oil/kerosene/gasoline
Color of smoke is black
cooking oil
Color of smoke is brown
wood/paper/cloth
Color of smoke is gray to brown
3 requirements to initiate and sustain combustion
Fuel must be present Oxygen must be available in sufficient quantity to combine with the fuel Heat must be applied to initiate combustion, and sufficient heat must be generated to sustain the reaction
From the least burned area to the most burned area
How is a fire scene searched?
Energy
The ability of a system or material to do work
heat, fuel, oxygen
The fire triangle consists of _____, _____ and _____
the physical state of the fuel and the temperature
Two factors that influence the speed of the reaction
Plants
Used to feed the fire (ex. rags, newspaper, wood shavings)
Ignition devices
Used to start the fire (ex. matches, capsules, candles, chemicals, gas)
The temperature of the fire and the type of material that is burning
What does information does the smoke and fire color give a fire investigator?
The victim was alive during the time of the fire
What does the presence of carboxyhemoglobin in the blood and soot in the trachea indicate?
Helium
What is the carrier gas the pushed the sample through the GCMS?
Murder in the 2nd degree and arson in the 2nd degree
What was Moises Blandon charged with?
Spontaneous combustion
a fire caused by a natural heat-producing process in the presence of sufficient air and fuel
Molotov cocktail
a glass bottle containing flammable liquid with a cloth rag stuffed into it and lit as a fuse
sniffer
a portable vapor detector that searches for traces of flammable liquid residues
Substrate control
a sampling of similar but uncontaminated control specimens from another area of the scene. In the laboratory, the criminalist checks this to be sure that is it free of any flammables.
Modus operandi
an offender's pattern of operation
Hydrocarbons
any compound consisting of only hydrogen and carbon
Accelerant
any material used to start or sustain a fire
overhaul
breaking stuff apart to make sure nothing else is burning
Glowing combustion
combustion on the surface of a solid fuel in the absence of heat high enough to completely burn (pyrolyze) the fuel.
Radiation
does NOT rely on any contact between the heat source and the heated object. In a fire, all surfaces that face the fire are exposed to radiant heat and burst into flames once the surface reaches its ignition temperature.
heat of combustion
excess energy given off as heat and light
Oxidation
the combination of oxygen with other substances to produce new products
Flammable range
the concentration range between the upper and lower limits for combustion
pugilistic stance
the contracted of the muscles caused by extreme heat
Pyrolysis
the decomposition of solid organic matter by heat
1215
the heat at which aluminum melts
1980
the heat at which copper melts
1400
the heat at which glass softens
2900
the heat at which sands melts
1000
the heat at which steel loses half its strength
Flash point
the lowest temperature at which a liquid gives off sufficient vapor to form a mixture with air so that it will support combustion. Occurs at 1100 degrees
Alligatoring
the pattern left by low burning; low burning is an indicator of high heat
Combustion
the rapid combination of oxygen with another substance; accompanied by production of noticeable heat and light
Ignition temperature
the temperature a fuel must reach to allow heat energy to exceed the energy barrier
Flashover
the temperature at which anything that can combust, will combust. Usually happens around 1100 degrees. When this occurs, it automatically means the death of any person trapped in the blazing room and it signals that the fire is in the second, or fully developed stage of combustion.
Conduction
the transfer of her between substances that are in direct contact with each other. Direct heat.
Convection
thermal energy is transferred from hot places to cold places when warmer areas of a liquid or gas rise to cooler areas in the liquid or gas