230 likes | 722 Vues
ARSON ANALYSIS IN FORENIC SCIENCE. KENDRA KOKOFU ANDREW MADOUTY SHANICE GRANT Bronx Community College Dr. John Molina~Co-Mentor Dr. Brennan~ Mentor. What Is An Arson Fire?.
E N D
ARSON ANALYSIS IN FORENIC SCIENCE KENDRA KOKOFU ANDREW MADOUTY SHANICE GRANT Bronx Community College Dr. John Molina~Co-Mentor Dr. Brennan~ Mentor
What Is An Arson Fire? • ‘Arson is committed when a person intentionally burns almost any kind of structure or building. Many states recognize differing degrees of arson, based on such factors as whether the building was occupied and whether insurance fraud was intended.’ As stated on the criminal law website.
Arson falls in with the second most death rates in the United States , with smoking being not to far in front. • In 1996 alone arsonist has killed more than 5oo Americans, leaving property damage at an astounding two billion. • Unfortunately arsonist are rarely convicted for their crimes. Only 16% of arson cases lead to arrest and only 2% of that lead to convictions. • Also more and more arson cases tend to be drug related, the National Fire Protection Association have found that between 20%-25% of arson cases are drug related.
Why Arson Fires? • Arson fires are set for various reasons. • Some people set fires for revenge (a cheating spouse, or someone who did you wrong), some are pyromaniacs and others set it for the insurance money. • Pyromaniacs are those who are obsessed with fire: they like how the blaze looks, the way it smells and the different colors. • Those who set fires for insurance money do not look into the facts and do not always realize the danger tha can befall them, for the fire can spread further than they wanted or expected or it can release toxic fumes into the atmosphere.
Accelerants • One of the most common ways in which an investigator can tell if the fire was purposely set is to find the accelerants. • Accelerants are a chemical fuel that causes a fire to burn hotter, spread more quickly than usual, or be difficult to take out and can also be used as evidence. • Gasoline, Kerosene, Turpentine and Diesel Fuel are the four most commonly used types of accelerants.
What is PID? • PID (Photo Ionization Detectors) helps to detect areas of higher hydrocarbons that may indicate the presence of accelerants. • They are very sensitive board spectrum monitors. • They measure hydrocarbon vapors in low concentrations from less than ppb(part per billion) to 10,000 ppm (part per million).
PID Continued… First you hold the end of the PID probe At the point where the accelerant may be present then listen or watch for signs of hydrocarbons. Second you check between cracks in the floor , ceilings, below floor boards, or even the unburned portion of the carpet or floor to find if any accelerant soaked in and remained. When or if hydrocarbons are detected you trace it back to the location with the maximum point of reading. When that is done you collect samples from that point to send the lab for further testing.
What is FID? • Flame Ionization Detectors are detectors that interact with solutes that are extracted from gas chromatography columns to produce a current. These detectors test samples of biochemical compounds, such as proteins, nucleotides, and many others.
FID Continued… In a Flame Ionization Detector, there is a thermocouple that is located between a jet and an electrode and has an output. The thermocouple is monitored as an increase in the flow of ions forms around a flame during combustion. The substance that the flame is heating then releases ions that provide a current to the amplifier. The overall job of the FID is to detect all the carbon compounds in the environment that is being tested.
What is GC? • Gas chromatography is used to separate the components of a mixture. • Chromatography in a general sense is used to separate mixtures of chemicals into individual components. Once the mixtures are separated ,the components can be evaluated individually. • In chromatography, Separation occurs when sample mixtures are injected into a Mobile Phase. In Gas Chromatography , The Mobile phase is an inert gas( such as helium.) • The Mobile phase then carries the mixture through the Stationary Phase. The Stationary phase is usually a chemical that can selectively attract components in the samples mixture.
Gas Chromatography Continued… • The stationary phase contains a tube of some sort. This tube is referred to as a column. A Column can be glass or stainless steel of various dimensions. • When the mixture of compounds in the mobile phase interacts with the stationary phase, Each of the compounds in the mixture interacts at a different rate. • Those that interact the fastest will exit the column first. Those that interact slowest will exit the column last. • To allow more compounds to come from this separation , The process can be altered by changing the temperature of the stationary phase or the pressure of the mobile phase.
Methodology • After the firefighters have finished extinguishing the fire, the Arson Investigators arrive only if the fire fighters think that the fire may not have been accidental. • The investigators then work at finding accelerants that may have been used, for example, kerosene, diesel, petrol and many more. • Also helping the investigators, chemist work mainly around the origin site trying to get samples of the ground, clothes or any other item that may have been used to either cause the fire or that may have soaked up the chemical used to start the fire.
Methodology Continued… • The samples are then properly bagged and sent to the lab in order to be further analyzed. • If the items at a house has been to neatly placed the investigators will be able to tell that it was not accidental. • For example, if all the windows were left open, and the fire seemed to follow a neat line, or started in two or more different places the investigators will be able to tell that it was not an accident.
1978 Arson Case • In 1978, Eric Jackson-Knight was convicted for setting a Walbaums Supermarket on fire in the Sheepshead Bay section of Brooklyn, New York. He was brought in for questioning due to a tip from an informant and the police said that he confessed to doing the crime. He was convicted for arson and for the death of 6 firefighters that died in the line of duty. After serving 10 years, his case was reopened and he was set free after the judge ruled that prosecutors withheld information, linking the fire to be caused by an electrical issue in the building.
Conclusion • When doing this research we came to the conclusion that forensic science does indeed have many different levels and sub-levels to it. • This project was done in the hopes of being able to show others that forensic science is not all about lab work, and dead bodies, but that there is more to it.
Bibliography http://www.afcintl.com/pdf/rae/ap207.pdf http://videos.howstuffworks.com/hsw/11816-forensics-solving-arson-crimesvideo.htm http://www.crimeandclues.com/arson.htm http://dictionary.reference.com/browse/arson http://criminal.findlaw.com/crimes/a-z/arson.html http://truthinjustice.org/arson.htm http://www.interfire.org/ http://www.njiaai.org/arson_facts.htm http://www.encyclopedia.com/topic/arson.aspx http://www.lititzmutual.com/arson.shtml https://www.nicb.org/cps/rde/xbcr/nicb/AM1244-NICB_ArsonBro2.pdf http://www.wisegeek.com/what-do-arson-investigators-look-for.htm http://www.crimeandclues.com/arson.htm http://www.ask.com http://www.google.com http://www.chromatographyonline.org/topics/flame/ionization/detector.html
Acknowledgements • Dr.Brennan-Mentor • Professor Molina~ Co-Mentor • Bronx Community College • Dr. Sat • HCS Staff • And All Of you For Listening.