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Catching Killers. FIRE INVESTIGATION. Catching Killers. FIRE INVESTIGATION. Used to be the ideal way for a criminal to make evidence go up in smoke Arson Investigation Unit N ew techniques & modern science VS fire pattern myths & personal judgment By exploring What makes fire
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Catching Killers FIRE INVESTIGATION
Catching Killers • FIRE INVESTIGATION Used to be the ideal way for a criminal to make evidence go up in smoke Arson Investigation Unit New techniques & modern science VS fire pattern myths & personal judgment By exploring What makes fire Reaction with different chemicals and solutions Advancements in the field Importance to Law First Responders to a Fire Case Studies Federal Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) Fire research lab Used to solve arson cases Planned test fires and cutting edge technology
Get the boring stuff out of the way… • Book Questions Chapter 24: Basic Fire & Explosion Investigation
House Fire Homicide In 2007, a house fire kills a middle aged couple, but leaves their teenage son nearly unscathed. • Do you think the suspect should have been charged with arson and murder? Why?
Fuel + Oxygen + Heat = Fire Heat Energy needed to increase the temperature of the fuel to change into the vapor state for ignition to occur. Examples: STOVES HEATING APPLIANCES FIREPLACES DAMAGED WIRING Fuel combustible material in any state of matter Examples: CLOTHING FURNITURE CURTAINS FLAMMABLE LIQUIDS The air we breathe is about 21% oxygen. Fire requires an atmosphere with at least 15-16% oxygen.
Fire Investigation Terms • Fire - Produced when a substance undergoes rapid oxidation involving heat and light. • Fire Triangle– Shows the three elements needed to produce and sustain a fire. • Flash Point – The lowest temperature to which a substance must be heated in order for the substance to give off vapors which will burn when exposed to a flame or ignition source. • 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. • Arson – A fire started deliberately.
Obvious Problems… • Difficult to evaluate scene • Scene & the crime are severely damaged • If not completely destroyed • Efforts of firefighters may destroy evidence • Spoliation may occur • By using physical & chemical evidence • Find the Point of Origin • What caused the fire • Determines if fire was accidental or incendiary (intentionally set) Successful Arson Investigation…
Common Reasons for Arson Crimes • Covering their tracks: • Cover theft, murder or other crime • Ex: Embezzler destroys company financial records • Insurance fraud: Monetary Gain • Need quick money • Insurance greater than the property’s marker value • Usually remove valuables and then try to claim insurance • Psychological reasons: Mentally Disturbed • To fulfill some deep-seated psychological need • Pathological love of fire may lead to starting structure or forest fires • Usually turns into serial offense • Revenge: Malicious Vandalism • Cause for burning someone’s house or business • Suicide or murder: • Bodies usually found in fire were dead before the fire started • Fire is too painful for suicide • Fire is too unpredictable for murder • Terrorism: • Create fear or make political statement
Fire Investigation:Remember??What should the first person to a crime scene do? • How First Responder's Impact The Fire Investigation • Write down what they take note of when they arrive at the scene (1) Observe(2) Preserve(3) Document(4) Communicate
Fire Investigation Basics: Time is the enemy: Many of the volatile substances that cause or accelerate a fire rapidly dissipate • Work from the least damaged areas to the most heavily damaged areas. • Document with notes, photographs, and videos. • Collect evidence (accelerant samples, fire items, and other crime scene evidence.)
Fire Investigation Basics: • Collect evidence (accelerant samples, fire items, and other crime scene evidence.) • Four methods accepted in court: exigent circumstances, consent of property owner, administrative search warrant, criminal search warrant. • Evidence containers – metal cans, glass jars, or special evidence bags • Through Observations, experiments • Use of Dogs or VTA – Vapor Trace Analyzer • Collect unburned materials for comparison purposes
Fire Investigation Basics: Time is the enemy: Many of the volatile substances that cause or accelerate a fire rapidly dissipate • Work from the least damaged areas to the most heavily damaged areas. • Document with notes, photographs, and videos. • Collect evidence (accelerant samples, fire items, and other crime scene evidence.) • Interview witnesses – including first responders • Determine the point of origin – requires understanding of how fire moves through a structure
Fire Investigation Basics: • Determine the point of origin – requires understanding of how fire moves through a structure • Fire moves horizontally and vertically from point of origin • Follows path of least resistance
Fire Investigation Basics: Time is the enemy: Many of the volatile substances that cause or accelerate a fire rapidly dissipate • Work from the least damaged areas to the most heavily damaged areas. • Document with notes, photographs, and videos. • Collect evidence (accelerant samples, fire items, and other crime scene evidence.) • Interview witnesses – including first responders • Determine the point of origin – requires understanding of how fire moves through a structure • Determine the heat source(s). • Hypothesize the reasons for the fire.
Fire Investigation Basics: • Hypothesize the reasons for the fire. • Subjective or speculative info cannot be included • Only facts that can be clearly proven by observation or experiment
Fire Clues • Point of Origin – Burn patterns and other damage can help determine the point of origin, or the location where the fire started. • Char Patterns– Created by very hot fires that burn very quickly and move fast along its path, so that there can be sharp lines between what is burned and what isn't. • A char pattern on a door would help an investigator determine which side of the door the fire was on. • A char pattern on the floor would help investigators determine the use of an accelerant and its path. • V-Patterns - Fire burns up, in a V-shaped pattern, so a fire that starts at an outlet against a wall leaves a char pattern that points to the origin. • A very narrow V-shape might indicate a fire that was hotter than normal, such as one helped along by an accelerant. • A wide V-shape might indicate a fire that was slow burning. • A U-shape could indicate that there was a "pool of origin" rather than a point of origin, such as might be caused by, say, a puddle of gasoline.
Heat Shadows- Occur when heavy furniture shields part of a wall; can help determine the origin point. • Glass - Glass fragments, windows, and light bulbs can provide clues to a fire. • Light bulbs tend to melt toward the heat source, so the "direction of melt" can indicate the direction of the fire. • The shattered or cracked glass of the windows can provide indications as to how a fire burned. • A dark soot layer on the glass could indicate a slow, smoldering fire. • Clear glass with an abnormal pattern of cracking could imply a very hot fire, possibly due to an accelerant. • Chimney Effect- Since fire burns upwards, there can be a "chimney effect" where the fire ignites at a point, the superheated gases rise upward and form a fireball, which continues straight up to burn a hole in the ceiling. If the roof is not entirely burnt, and the fire investigator finds such a hole, the origin of the fire could be directly underneath. • Color of smoke – Determine what type material was burning • Color of flames– Indicates at what temperature the fire was burning.
Image: Havana Rural Fire Department Accident or Arson? • 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
Arson Facts in America According to the FBI Crime Index, juvenile and adult arson cause an annual average of 560,000 fires, 750 deaths, 3,700 injuries, and $1.5 billion in property loss. 55% of all arson arrests in the US are children under 18. Juvenile Firesetting Fires set by juveniles are usually the result of a child or teenager experimenting with fire with a lack of understanding of the consequences. Others fires may be started by troubled children as a “cry for help” or as acts of vandalism. These tragic events are not isolated incidents. In a typical year, in the U. S., 300 people are killed and $190 million in property is destroyed in fires set by children. Children themselves are usually the victims of these fires accounting for 85 of every 100 lives lost.
Investigating Homicidal Fires:Can structural fires destroy a body? • No! • Do not burn hot enough • Bodies can remain well-preserved internally • Medical Examiner can still search for sign of trauma and poisons
Investigating Homicidal Fires • Determination of the position the body was found in • Use items around the body as well • Carbon monoxide levels in the blood and tissues • Asphyxia (Suffocation) – Primary cause of death in fatal fires • High level of CO = died from smoke • Low level of CO = dead before or at the time the fire started • Presence or absences of soot in the lungs and airways • Similar to CO levels