Crime Scene Investigation: Offense Investigations

Introduction to Criminal Investigation

• The objective of a criminal investigation is to gather evidence and identify the perpetrator of a crime
• A procedure for conducting an investigation will be discussed, including the main objectives and steps taken in a preliminary investigation

Types of Bombs

• Explosive Bomb: causes damage by fragmentation, heat, and blast wave
• Incendiary Bomb: constructed with flammable materials designed to produce a burning effect

Laws Pertaining to Arson and Explosives

• Arson (Class A, B, or C Felony): knowingly damaging a building or inhabitable structure by starting a fire or causing an explosion
• Knowingly burning or exploding (Class "D" Felony): knowingly damaging property of another by starting a fire or causing an explosion
• Reckless burning or exploding (Class "A" Misdemeanor): recklessly damaging or destroying a building or inhabitable structure of another by knowingly starting a fire or causing an explosion
• Negligent burning or exploding (Class "B" Misdemeanor): with criminal negligence causing damage to property of another by fire or explosion
• Causing catastrophe (Class "A" Felony): knowingly causing death or serious physical injury to ten or more people; or substantial damage to five or more buildings or inhabitable structures
• Possession, manufacture, transport, repair, or sale of certain weapons prohibited (Class "C" Felony)
• Bombing and other explosive matter upon bus or near bus terminal (Class "A" Felony)
• False Bomb Report (Class "A" Misdemeanor): knowingly making or causing to be made a false report to any person that a bomb or other explosive has been placed in a public or private place or vehicle

Bomb Threat Response Procedures

• Turn radio off when nearing the scene to avoid detonating an explosive device
• Contact the manager or person in charge of the building
• Building search should be conducted by personnel familiar with the premises, with police assistance if necessary
• Evacuation procedures:
  • Evacuate everyone if an explosive device or suspected device is found
  • Be aware of the possibility of a second device
  • Post guards at entrances
• Evacuation distances depend on the size of the explosive device:
  • Small device (up to 5 lbs.): up to the size of a shoe box or lunch box
  • Medium device (up to 10 lbs.): small attaché case/large handbag
  • Large device (up to 50 lbs.): large suitcase
  • Unknown sized device: secure perimeter of 300 feet

Bombing Scene Procedures

• Establish a perimeter by locating the furthest piece of debris from the blast seat
• Limit admittance to the scene to authorized personnel
• Use one entry/exit path to minimize the chance of destroying fragile evidence
• Be cautious of secondary devices while securing the perimeter

Elementary Chemistry of Fire

• Four elements of fire: heat, oxygen, fuel, and uninhibited chain reaction
• Heat is transferred in three ways: conduction, convection, and radiation
• Phases of structural fires:
  • First Phase (incipient): fire produces gases, rapid progress after flaming starts
  • Second Phase (free burning/flame producing): major involvement, convection heating
  • Third Phase (Smoldering): burning is reduced to glowing embers, toxic/flammable gases present

Explore the primary objectives and procedures of a criminal investigation, including the main objectives and steps of a preliminary investigation.