1 Book Cover Here Chapter 21 ARSON AND EXPLOSIVES Criminal Investigation: A Method for Reconstructing the Past, 7 th Edition Copyright © 2014, Elsevier

1

Book CoverHere

Chapter 21

ARSON AND EXPLOSIVES

Criminal Investigation: A Method for Reconstructing the Past, 7th Edition

Copyright © 2014, Elsevier Inc. All Rights Reserved

2

Unusual Aspects of Arson

1. Fire may consume traces of its incendiary origin

2. Crime scene may be destroyed by water3. Timing device may have been used – enables

alibi4. Falling debris/building collapse may destroy

evidence5. Freezing/hot weather may delay or prevent

searchCopyright © 2014, Elsevier Inc. All

Rights Reserved

3

Definitions

• Elements of the crime differ more from state to state than any other crime

• Keyed to the endangerment of life• When was the fire started? • Was a person in the structure, or was it

reasonable to expect anyone to be?


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Corpus Delicti

1. Fire or burning occurred in a structure or property

2. The fire or burning was intentional, not accidental or attributable to negligence or natural causes

3. Someone set the fire, caused it to be set, or otherwise furthered the act


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Why is Arson Suspected??

• A fire is considered to be of accidental origin unless proven otherwise.

• Hard to prove the fire was not accidental, even though suspicions and experience say otherwise

• Question all information until it is verified• Every fire scene should be treated as a

potential crime scene• Working hypothesis


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People as a Source of Information

• Who Discovered the Fire?• Firefighters • Owner or Manager of the Structure • Employees • Insurance and Financial Personnel • Business Competitors• Other Possible Witnesses


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Conducting the Investigation

1. Case assigned to an investigator2. Investigator plans investigation and

assembles tools, equipment, and personnel3. The scene is examined and data is collected4. Physical evidence is collected, documented,

tested, and evaluated5. The scientific method is used to analyze the

information obtained


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Fuel+

Oxygen+

Heat Source =

COMBUSTION


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Combustion• Fuels• Oxygen• Heat sources

– Accidental Heat Sources– Heating / Cooking Systems – Electrical System (Equipment and Appliances)– Smoking – Matches – Natural Heat Sources

• Investigative Significance• Accelerants


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Point of Origin

• Locating the Initial Site – Fire Patterns

• Pour Patterns• Alligatoring• “V” Pattern • Charring

– Heat Distortion • Light Bulbs• Spalling • Crazing


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Significance of Finding Point of Origin

• Ignition Sources • Plant (Arson Set)

– Timing Devices– Matches, Candles, Cigarettes, and Other Timing

Devices– Trailers

• Accelerants – Detection Methods – For Use at the Crime Scene – Collection and Transmission


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Motive• Financial Gain

– Insurance Fraud– Elimination of Competition – Moving and Resettlement Allowance

• Intimidation – Fear for Safety– Threatened Economic Loss– Change of Policy

• Emotional Reasons– Jealousy– Spite– Revenge– Hatred


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Motive continued

• Concealment of Another Crime – Homicide – Larceny– Fraud, Forgery, or Embezzlement– Other Crimes

• Pyromania• Recognition • Vandalism


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Records and Follow-Up

• Fire Records• Straw Owners• Persons of Interest

– Bills– Accounts receivable– Taxes and tax liens

• Direct and Circumstantial Evidence


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Bombing Investigations: Explosives• SEMTEX• C-4• HMEs (Home Made Explosives)• IEDs (Improvised Explosive Devices)• Triavetone Triperoxide (TATP)• Peroxide-Based Explosive • Pipe Bomb• Plutonium-229• TNT (Trinitrotoluene)• Ammonium Nitrate


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Types of Bombs

• Car bombs• Fragmentation bombs• Letter bombs• Aircraft bombs• Suicide bombers


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Primary Effects of Detonation

• Fragmentation• Blast Pressure• Fire


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Conclusion

• Arson & Explosives = Specialized investigations• Assistance of trained specialists often

warranted• Military hardware (rocket-propelled grenades;

shoulder-mounted missiles) pose increasing threats

• Bombs/explosives may have terrorist underpinnings


Documents

1 Book Cover Here Chapter 21 ARSON AND EXPLOSIVES Criminal Investigation: A Method for Reconstructing the Past, 7 th Edition Copyright © 2014, Elsevier