Fire as Evidence

1. Fire as Evidence

2. Forensic FilesBurning Desire • https://www.youtube.com/watch?v=RSYw7ykGiuI

3. Securing the Crime Scene • Keep everyone SAFE • Prevent evidence destruction/tampering

4. CSI Teams Responsibilities • FIND the evidence • EXAMINE the evidence • EVALUATE the evidence

5. Evidence • Every contact leaves a trace • Direct- • Circumstantial-

6. Class evidence-Color (hair,skin, eyes) height, clothing, blood type, types of weapons • Individual- • Trace-hair, fibers, blood spatter

7. Chain of Custody • Documentation that follows evidence from crime scene to court room. Provides evidence of everyone in contact with evidence • Importance-establishes that evidence is valid

8. Crime Scene reconstruction • Use of scientific methods, physical evidence, deductive and inductive reasoning” to understand the series of events that led to the occurrence of a crime.

9. Arson • Arson – a CRIMINAL act of starting a fire.

10. Difficulties in Arson Detection • 1. fire destroys evidence • 2. carefully planned • 3. arsonist leaves crime scene • 4. accelerants evaporate quickly

11. Signs of arson? • 1. Multiple points of origin • 2. evidence of an accelerant • 3. streamers • 4. separate , but connected fires

12. Streamers • Separate but connected • fires

13. Fire Investigation Terms • Point of Origin– The location where the fire started. • Burn patterns–Noticeable patterns created by the fire as it burns. • Accelerants – Substances, such as gasoline, paint thinner, and alcohol, that accelerate the burning process. • .

14. Fire Clues • Char Patterns-sharp lines between what is burned and what isn't. • V-Patterns - Fire burns up forming aV-shaped pattern, points tothe origin. • A very narrow V-shapemight indicate a fire that was hotter than normal, such as one helped along by an accelerant. • A wide V-shapemight indicate a fire that was slow burning. • A U-shape could indicate that there was a "pool of origin"

15. Clues from GLASS -windows, light bulbs… • Light bulbs tend to melt toward the heat source • The shattered or cracked glassof the windows can provide indications as to how hot the fire was. • A dark soot layer on the glass could indicate a slow, smoldering fire. • (Direction, Temperture, Duration)

16. Chimney Effect- fire burns • the superheated gases rise straight up to burn a hole in the ceiling. • https://www.youtube.com/watch?v=xr6b9b8FYKk • https://www.youtube.com/watch?v=hMtjGfr0tYs • https://www.youtube.com/watch?v=v3F4c5o4J7M

17. https://www.youtube.com/watch?v=QqMVm72FMRk • https://www.youtube.com/watch?v=InrS4Fdndr4

18. Color of smoke– Determine what type material was burning  Color of flames – Indicatestemperature

19. EXAMPLES OF BURN PATTERNS • Alligatoring • Depth of char • Breaking of glass • Spalling • Distorted light bulbs • Temperature determination 18-8

20. Alligatoring

21. Char=Burned • Depth of char • Clues to how fire spread • Clues to the duration (Source: Factory Mutual Engineering Corporation, Norwood, Massachusetts. Reprinted with permission.) 18-9

23. Fire Investigation Basics • Work from the least to most damaged. FIND POINT OF ORIGIN • Documentwith notes, photographs, and videos. • Collect evidence (accelerant samples, fire items in AIRTIGHT container) • Interview witnesses • Determine possible cause

24. Fire ClassificationCan you give an example? • Accidental • Natural • Intentional -Arson • undetermined

25. COMMON MOTIVATIONS FOR ARSON • $$$-insurance fraud, for profit • Revenge, spite, jealousy • Vandalism/malicious mischief • Racial/religious hostility • Crime concealment/diversionary tactics • Psychiatric afflictions Vanity, hero fire 18-15

28. Accelerant remains can be detected by tracing the point of origin or canine use. Fire > Collection Collection of Evidence Object containing accelerant must be packaged in air tight container.

29. Collection At the suspect point of origin of a fire, ash and soot, along with porous materials which may contain excess accelerant, should be collected and stored in airtight containers, leaving an airspace to remove samples.

30. Collection Traces of flammable liquid residues may be located with a vapor detector (sniffer). It is important that a sampling of similar but uncontaminated control specimens be collected. A search for ignitors such as matches, an electrical sparking device, or parts of a “Molotov cocktail” must also be conducted.

36. Arrow pattern of burning, showing fire travel.

37. Arson or Nah? • Accidental Nature • Heating System • Electrical appliances • Lightning • Children playing with matches • Smoking • Non-Accident • Odors – Gas, kerosene, or other accelerants • Furnishing – Removal of personal objects and valuables • Clothing – Check debris for buttons, zippers, etc • Locked windows, blocked doors • Two or more points of origin • Look for inverted v-patterns (can be a sign that an accelerant was used) • Floors charred –Can indicate use of an accelerant • Trailers that lead the fire from one place to another

38. Arsonist • http://www.firelineschool.com/student_files/10%20Famous%20Arsonists%20and%20Why.pdf