1. Do-now o Have “Happy Land Fire” out o In your notes, answer the following: What do you need to start a fire? What precautions are taken in most buildings to ensure that fires don’t occur?

2. Chapter 4 Arson and Fire Investigation © 2012 Cengage Learning. All Rights Reserved

3. 3 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Introduction—Objectives 1. Define combustion reactions. 2. Discuss the four factors that are required to ignite and maintain a fire. 3. Explain the conditions in which fuels will burn. 4. Examine reasons why arson is difficult to detect. 5. Identify the four categories of fire.

4. 4 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Introduction—Objectives 6. Evaluate the significance of burn patterns discovered at an arson investigation. 7. Discuss the proper methods for detecting, collecting, preserving, and analyzing arson evidence. 8. Describe the psychological profile of an arsonist. 9. Examine the various motives for arson.

5. 5 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Introduction—Vocabulary o accelerant - in fire investigation, any material used to start or sustain a fire; the most common are combustible liquids o arson - the intentional and illegal burning of property o combustion reaction – oxidation reaction that involves oxygen and that releases heat and light o exothermic reaction – chemical reaction that releases heat o heat of combustion - excess heat that is given off in a combustion reaction

6. 6 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Introduction—Vocabulary o hydrocarbon - any compound consisting only of hydrogen and carbon o oxidation reaction - the complete or partial loss of electrons or gain of oxygen o pyrolysis - decomposition of organic matter by heat in the absence of oxygen o substrate control - a similar, but uncontaminated, sample; used for making comparisons

7. Happy Land Fire o https://www.youtube.com/watch?v=3PS1Ii4- 3u0 https://www.youtube.com/watch?v=3PS1Ii4- 3u0 7 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved

8. 8 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved 8 Happy Land Fire o Julio Gonzalez and Lydia Feliciano dated off and on for six years. o When Lydia ended the relationship, Julio set fire to the Happy Land Club in the Bronx. o 87 people were trapped and died. o Julio purchased the accelerant at a local station. o Julio’s home and shoes smelled of gasoline.

9. 9 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Chemistry of Fire (Obj 4.1, 4.2, 4.3) o Fire — a rapid oxidation reaction that involves a combustible material o Oxidation — the complete or partial loss of electrons or the gain of oxygen 2Na + Cl 2  2NaCl

10. 10 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved

11. 11 Combustion o Combustion reactions — oxidation reactions that involve oxygen and produce flames o Heat of combustion — excess heat energy o Exothermic reactions — chemical reactions that release heat

12. 12 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved The Fire Tetrahedron Four ingredients are required to start a fire and keep it burning Oxygen Fuel Heat Chain reaction

13. 13 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Flash Point & Ignition Temperature o Most accelerants are hydrocarbons in a gas state o Hydrocarbons are compounds that are made of only hydrogen and carbon atoms — gasoline, kerosene, lighter fluid o In a gas state, molecular bonding is weaker o Vaporization — liquid changes to gas o Flash point — lowest temperature at which vaporization occurs

14. 14 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Flash Point & Ignition Temperature

15. 15 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Pyrolysis o pyrolysis - decomposition of organic matter by heat in the absence of oxygen o The vapors given off from the resins in wood are flammable and will burn.

16. Do-now: o Hand in lab sheet, if you have not done so. o Discuss, with your neighbor, the following, and answer in your notes (I will come around and check them) How might you determine if a fire is intentional? What is the role of a fire investigator and how does it differ from a firefighter? 16 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved

17. 17 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Arson is Difficult to Prove o The crime is usually carefully planned. o The arsonist leaves the scene before anyone notices a fire. o The fire destroys evidence. o Extinguishing the fire also destroys evidence.

18. 18 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Function of a Fire Investigator o Investigation must begin quickly, before evidence is lost o Find the fire’s point of origin o Examine possible causes Accidental Arson o Classify the fire

19. 19 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Function of a Fire Investigator

20. Burn Patterns 20 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved

21. Burn Patterns 21 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved

22. Burn Patterns 22 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved

23. 23 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Determining Cause

24. 24 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Determining Cause

25. 25 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Collecting the Evidence o Do you need to obey the fourth amendment? o Begin immediately; no warrant required o Collect 3-4 liters of ash from point of origin and other suspected areas o Use portable vapor detectors, or sniffers o Use trained dogs to sniff

26. 26 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Collecting the Control o Place each sample in its own container o Collect a substrate control — a debris sample that has not been contaminated by the accelerant o Comparisons to the substrate control may help prove an accelerant was used o Some products may look like accelerants when burned

27. 27 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Packaging the Debris o Use airtight containers such as a new clean paint can and lid o Leave head space at the top of the can

28. 28 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Finding the Igniter o Matches — often burns in the fire o Cigarette lighters — often removed by arsonist o Molotov cocktail — may leave glass fragments o Faulty electrical wiring — an arc causes a predictable pattern o Knowing the igniter helps form the criminal profile

29. 29 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Lab Analysis o Heat the debris container to collect vapors in the head space o Direct headspace extraction procedure Remove vapors with a syringe Analyze vapors with gas chromatography o Passive headspace extraction procedure Suspend a charcoal-coated strip inside the can Replace lid Heat container 4-16 hours at 50-80 o C Charcoal absorbs the vapor

30. 30 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Lab Analysis Passive headspace extraction procedure

31. Homework o Read “Berns Triplets” and “John Orr”, p. 118- 119 o Answer ALL think critically 31 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved

32. Do-now o Have HW: Case Studies on desk o Take “Investigations” Activity and work on it IN PAIRS with YOUR NEIGHBOR! (One per pair) p. 130-131 32 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved

33. Backdraft o http://www.youtube.com/watch?v=61XUb28jk UI http://www.youtube.com/watch?v=61XUb28jk UI 33 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved

34. 34 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Psychology of an Arsonist o Sense of power o An emotional high o No typical arsonist; possible characteristics: Less than 25 y.o. Father not in the home Domineering mother Academically challenged Emotionally and/or psychologically disabled Unmarried Living with parents Inadequacy, insecurity Fascination with fire Alcoholism Parental neglect or abuse

35. 35 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Motives for Arson o Financial gain — insurance fraud o Revenge, spite o Excitement o Vanity, hero syndrome o Crime concealment — destroy evidence o Vandalism

36. Homework o Study for Chapter 4 quiz- arson and fire o Finish Lab 36 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved

37. 37 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Chapter Summary o Fire is an oxidation reaction that involves a combustible material. Not all oxidation reactions produce fire. o The fire tetrahedron represents the four requirements for sustained fire—oxygen, fuel, heat, and a chain reaction. o Most fuels are hydrocarbons and typically have very high ignition temperatures. o The ignition temperature is when a fuel will light and continue to burn even if the heat source is removed.

38. 38 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Chapter Summary o The initial focus is to find the fire’s point of origin o The burn pattern helps determine whether the fire was natural, accidental, or deliberate. o Ash and debris are collected from the point of origin and any other suspected area. o Each sample of debris is placed in a separate airtight container.

39. 39 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Chapter Summary o For comparison purposes, investigators also collect a substrate control. o Two methods of collecting accelerant vapors for analysis are: direct headspace extraction procedure and vapor concentration. o Gas chromatography is used to analyze the accelerant residue — comparing the lab chromatogram with one of known hydrocarbons.

40. 40 Forensic Science II: Arson and Fire Investigation, Chapter 4 © 2012 Cengage Learning. All Rights Reserved Chapter Summary o Arsonists tend to exhibit a set of characteristics that helps investigators focus their search. o Most of the motives fit into six broad categories — financial gain, revenge, excitement, vanity, crime concealment, and vandalism.