PERIOD 8 forensic aspects of arson investigation

Use the information you recorded from the Forensic Files episode "Burning Desire" to fill in the blanks with the missing information. In this section, you will have a drop down box under each blank to help you find the correct word or words to fill in the blanks. The investigators knew the time of the fire because the clock had melted and thus stopped at 7:30. The origin of the fire was a v-shaped pattern that moved up and out away from the couch, where Sandy's body was found. She was face down on the couch. She was not wearing a shirt. She had a vertical gash on the back of her head. The toxicology report showed a blood alcohol level of .25, carbon monoxide levels of only 8%, and very little soot in her trachea. These all indicated she did not die in the fire. She also had bruises on her back and neck, indicating someone held her down to suffocate her.The bloody clothes were later found buried in a hamper in the basement. There were trailers from tissues stuffed into the couch which indicated somebody tried to encourage the spread of the fire, even though the fire burned out because no windows were left open. There was an empty vodka bottle near the couch.The evidence was packed in an airtight container and sent to the lab. The gas chromatography analysis showed no signs of any accelerant. The arson investigator concluded that the vodka was probably the accelerant because of the zig-zag pattern on the burned carpet, the empty bottle, and because it would burn up completely.John admitted on a video tape that he was present at Sandy's house the night of the fire, even though he denied this all along. He also said that she did not die in the fire, but if he didn't commit the crime, he wouldn't have known that.The conclusion was that he set the fire to cover up the murder of Sandy. He didn't want her to get half of his pension in the divorce. His sentence was life in prison without parole. Accidental Causes of Fire Please list 3 accidental causes of fire as discussed in class. A person commits arson when he knowingly damage any property of another person without his or her consent damage any property with the intent to defraud an insurer deliberately sets a fire with criminal intent all of these define arson The AI is responsible for many things at the scene of a fire. Which of these is not one of them? reconstruct things used to start the fire determine the identity of the arsonist determine motive detect chemical materials collected at the scene Fill in the blanks regarding the definition of fire. Fire is a type of oxidation, which is the combination of oxygen with other substances to create new ones. There are two processes by which this can occur: combustion, where heat or light are required, or rusting, where heat or light are not required. Of these two processes, fire is a type of combustion.To initiate and sustain combustion you need a fuel, which is any material that releases energy when it burns, enough oxygen to combine with the fuel, and enough heat to initiate and sustain combustion. These three things make up the fire triangle. If all three elements are not present at all times, a fire cannot be initiated and sustained. Open flames, sparks, static electricity, or hot surfaces are all examples of: auto-ignition temperatures ignition sources fuels accelerants Flammable means able to be set on fire. A flammable liquid, then, is one that: can be directly ignited gives off vapors that can ignite and burn when an ignition source is present will ignite when the auto-ignition temperature is reached ignites on its own without an ignition source Flammable Liquids Name two flammable liquids commonly found in most homes. When a substance is able to turn into a gas (vaporize), it is known as: volatile flammable combustible ignitable Accelerants Accelerants are substances that are used to aid in the spread of fire. Combustible liquids are almost rarely entirely burned up, and thus can be analyzed in the lab using gas chromatography. The two most common accelerants are gas and kerosene. As soon as the fire is extinguished, the AI first needs to: find the fire's origin rule out accidental cause look for signs of arson determine a motive Categories of Fires Match the fire categories with their descriptions. natural caused by acts of nature (lightning strike, intense sunlight accidental unintentional and explainable, without design or intent undetermined cause is unknown and cannot be identified deliberate intentionally set Streamers at a fire scene are: items used to ignite a fire paper products trails of accelerants used to spread fire from one area to another fans or open windows to create air for the fire Severe burning on the floor instead of the ceiling can be a sign of arson because: fire normally moves upward but if an accelerant is used, the origin is at the lowest point where the accelerant was poured and showing most the intense burning fire normally moves upward but if an accelerant is used, it will burn out before it gets to the ceiling fire normally moves upward but if an accelerant is used, the origin is at the highest point where the accelerant did not touch severe burning on the floor instead of the ceiling is never a sign of arson All of these are signs of arson except: multiple originpoints separate and unconnected fires a bystander who appears at multiple scenes forced entry or missing items all of these ARE signs of arson Why do people commit arson? Name two reasons - they must correspond to reasons listed in class. To collect fire evidence, always use a(n): plastic bag paper bag evidence pouch airtight container Evidence at a Fire Scene List 3 items from our classroom discussion that would be considered as evidence at a fire scene. Since deliberate fires are intentionally set, then alldeliberate fires are arson. true false Use the information you recorded from the Forensic Files episode "Hot on the Trail" to fill in the blanks with the missing information. In this section, there is no word bank so I hope you paid careful attention! Please be careful with spelling and grammar. In this episode, the initial string of fires were believed to be deliberately set because in each one, there were people in the house, the fires were set on the front or back porch, there were remnants of a melted plastic container with cloth wick made from an athletic sock, and they occurred between 2 and 6 am at single family homes. The ATF found remnants of white plastic shopping bags that they believed were used to carry the gallons.When they checked a list of fires over the past year, there were an astonishing 20 additional fires that appeared to have been set the same way. The criminal profiler said the offender was likely a black male in his 20s-40s, and unmarried because he was going out in the middle of the night.For the next two months, there was a fire each week...until there was a piece of cloth sock that survived the fire. DNA from skin cells on the sock showed a clear profile, but there was no database match. Then at 2am one night, 3 young men confronted a man in the street they thought was a robber. He left behind a bag with plastic gallons of gasoline and a sock tied to the handle. They found a single human hair sticking to the container and the DNA in the root was a match to the sock DNA.Shortly after this, the arsonist switched to black plastic bags. In the entire country, these bags were only used by two stores, and both were in the vicinity of the fires. An arson dog detected the presence of gasoline on a pair of military dress pants found discarded across the street from one of the fires. The skin cells on the pants matched both previous DNA samples. The NCIS investigators said they were also looking for an arsonist who set fires to cars in a military parking lot. On surveillance they identified Thomas Sweat's car leaving the lot, but they had no proof of anything so they decided to follow him for 24 hours. It turns out he lived right near one of the stores that used the black bags, so they brought him in for questioning. At first, he denied everything, but willingly gave a DNA sample. It matched all the previous samples. He confessed to not only the recent fires, but some dating back 25 years. The total amounted to over 350 fires! The motive was never revealed but he did say in court that he heard voices, and he was under a lot of stress. He got two consecutive life terms and no parole, plus an additional 135 years in prison.