Arson and Bombing Investigations Chapter 18. Copyright ©2008 The McGraw-Hill Companies, Inc. All...

Arson and Bombing

Investigations

Chapter 18

Copyright ©2008 The McGraw-Hill Companies, Inc. All rights reserved.

2

THE CRIME OF ARSON• Involves the destruction of both property and,

potentially, human lives.• Who Investigates?– Fire department– Police department

• Unfortunately, in most areas neither department on its own has sufficient resources to investigate this crime as thoroughly as other types of crimes are investigated.


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LEGAL ELEMENTS OF THE CRIME OF ARSON

• Arson– Malicious and intentional or fraudulent burning of buildings

or property.– mens rea is an important element of the crime of arson:

Proof of intent must show that the act was done voluntarily, knowingly, and purposely.

– Simple arson • Malicious and intentional or fraudulent burning of buildings or

property that does not create an imminent risk or threat to human life.


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• Aggravated arson – Malicious and intentional or fraudulent burning of

buildings or property and knowingly creating an imminent danger to human life or a risk of great bodily harm to others.

• Attempted arson– The demonstrated intent to set a fire coupled with

some over act toward actually setting the fire.


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• Negligent fires – Fires that occur or become uncontrollable as a

consequence of culpable negligent behavior, resulting in damage or injury to property or people.


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MOTIVES FOR ARSON

• There can be many motives for arson.– Fraud fire– Potential monetary gain from insurance as a result

of a fire.– Insurance adjuster or contractor seeking additional

work.– Firefighters or security officers, who seek

recognition for their heroism in fighting the blaze.


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MOTIVES FOR ARSON

• Motives can be divided into two broad categories: – Rational • includes goals such as revenge or profit

– Irrational • typically are not goals and are related to uncontrollable

urges or various mental disorders


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Fire Classifications

• The major classifications for fires are natural, accidental, criminal, suspicious, or of unknown origins.– Natural Fires• Include those used to burn leaves or refuge or fires set in

a campfire or other type of safety ring or burning area.

– Accidental Fires• May occur from a number of causes


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Fire Classifications

• Criminal or Incendiary Fires– Involve fires set intentionally and maliciously in an effort to

destroy property, buildings, or other structures or to conceal evidence of another crime.

• Suspicious Fires– A suspicious fire appears on the surface to have elements of

arson, but it may not be demonstrated as being intentional• Unknown Origin Fires– There is no apparent evidence of the cause. It is impossible

to determine whether these fires are accidental, natural, or criminal.


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INVESTIGATING ARSON

• Determine where and how the fire started– accidental or natural causes

• Accelerant – A booster such as gasoline, kerosene, or paint thinner added

to a fire to speed its progress.– When any firesetting device, igniter, or accelerant is found

near the site, the fire may be classified as an incendiary fire.– Such evidence is an indication of arson.– Incendiary fire

• A fire in which a fire-setting device, an igniter, or an accelerant is found.


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INVESTIGATING ARSON

• Since arson does not have an immediate corpus delicti, it is the responsibility of the investigator to show that a specific fire occurred and was deliberately set.

• Typically, investigators begin their investigation of suspected arson by examining the outside of a structure.

• Investigators must seek both direct and circumstantial evidence.


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INVESTIGATING ARSON• Fire triangle – The three basic elements for a fire: oxygen, fuel, and heat.– One or more of these elements is usually present in

abnormal amounts in the area of an arson.• Direct ignition – Setting a fire by directly applying a flame.

• Delayed ignition– Setting a fire indirectly by means of a mechanical, chemical,

or other timing device.• The crime of arson is generally committed under cover

of darkness, at a time, and in a manner calculated to divert suspicion.


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Burn Patterns• Burn patterns show the effects of burning or partial

burning during the fire. • These patterns are important elements in determining

the point of origin, the spread of the fire, the temperature, the duration, and the presence of accelerants

• V Pattern– When a fire is unobstructed and has an upward draft, flames

tend to fan up and outward, creating a V- or cone-shaped burn pattern similar to the sooty residue left on fireplace back walls.

– The point of the V usually leads to the source of the fuel in the fire.


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Burn Patterns

• Alligatoring– A scalelike burn pattern on wood. – Large scales indicate rapid, intense heat– Small, flat scales indicate low-intensity heat over a long

period of time.• Pour or Spill– The boundary between burned and unburned material. – It is caused by pouring some type of liquid accelerant on a

floor or surface and then igniting it.• Depth of Charring– Can indicate the intensity of the heat, the duration of a burn,

and the point of origin.


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Burn Patterns

• Crazing– Irregular cracks and lines in

glass and ceramic materials caused by rapid, intense heat.

• Spalling – Chipping, crumbling, or flaking

of cement or masonry caused by rapid, intense heat.


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Burn Patterns

Smoke• Color of smoke could indicate the material used

to start the blaze.– Black smoke • material may have contained petroleum

– White smoke • indicates vegetation


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Arson Indicators

• Multiple Points of Origin– Ensures better combustion and more complete destruction.

• Odors– Gasoline (the most common accelerant), kerosene, paint

thinner, and other flammable liquids have distinctive odors.

• Speed and Spread of Fire– Fires that seem to spread extremely rapidly and engulf major

portions of a building or structure very quickly may be considered suspicious.


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Arson Indicators

• Holes in Walls or Floors– Arsonists sometimes chop holes in walls or floors to

expose raw wood or to improve the draft for the fire.

• Alarm Tampering– Destroy or disabled alarms or sprinkler systems

• Trailer – A material (rope or rags soaked in accelerant,

shredded paper, gunpowder, fluid accelerant, and so on) used to spread a fire.


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Arson Indicators

• Intensity of Heat• Intense heat may be a clue that flammable

liquids or compounds were added to the burning materials.


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Cooperation among Arson Investigators

• Different agencies, often with joint jurisdiction, investigate suspicious fires.

• In some larger cities, a suspicious fire may be investigated by special units from the fire and police departments.

• In other cities and in unincorporated townships, a suspicious fire may be investigated by the state fire marshal, the state police, the sheriff ’s department, local fire investigators, or perhaps local town or borough police officers.


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Cooperation among Arson Investigators

• As a general rule of thumb, it is the fire department’s role to determine the nature and origin of the burning.


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Steps in an Arson Investigation


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CRIMINAL BOMBING

• Bombing – An incident in which a device constructed with

criminal intent and using high explosives, low explosives, or blasting agents explodes.

• The main functions of any police agency in a bombing incident are to:– protect human life and property– remove the bomb menace, if possible– investigate and apprehend the bombers or

threateners


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Explosives• Explosive – Any material that produces a rapid, violent reaction when

subjected to heat or a strong blow or shock.

• Explosives may be solids, liquids, or gases.• All explosives consist of:– a fuel– an oxidizer (a substance that supplies the oxygen to make

the fuel burn)– a detonator

• Generally speaking, there are four types of explosives.


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Explosives• Primary Explosives– These explosives are extremely sensitive to heat. Even a

spark of static electricity can cause them to explode. – They must be handled in small quantities and are used

chiefly as detonators to set off other explosions.• High Explosives– An explosive material in which the rate of change to a gas is

very rapid; explodes only upon the shock of a blasting cap, a detonation cord, or an electric detonator; includes nitroglycerin, TNT, RDX, and plastic explosives.

– High explosives are relatively stable.– They explode only upon the shock of a blasting cap to which

a fuse is attached, a detonating cord, or an electric detonator.


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Explosives• Low Explosives– An explosive material in which the rate of change to a

gas is quite slow; the material deflagrates, or burns rapidly, rather than exploding

– Includes black powder, smokeless powder, and fertilizers.

– They deflagrate, or burn rapidly, rather than explode.

– Must be ignited by heat, friction, or a spark.


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Explosives

• Blasting Agents– These explosives are the safest and least

expensive. – They are widely used in industry to shatter rock in

excavation and mining. – Common blasting agents include dynamite and

mixtures of ammonium and fuel oil.


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Explosive Accessories

• Evidence of the mechanism used to detonate the bomb.

• Blasting Caps– Used to set off, or ignite, high explosives.– Occasionally, caps are connected to lighting circuits. When

the lights are turned on, the bomb explodes.

• Safety Fuses– Safety fuses convey a flame through a medium at a

continuous and uniform rate to a nonelectric blasting cap.


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Explosive Accessories• Detonation Cords– Round, flexible cords, similar in appearance to

safety fuses. – The explosive core of a detonation cord is protected

by a sheath of various textiles, waterproofing materials, or plastics.

• Electric Squibs– Also are known as electric matches– The squib provides a spurt of flame or sparks similar

to that provided by a burning fuse.


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TYPES OF BOMBS

• Pipe Bombs– Black powder or smokeless powder is frequently

used to load pipe bombs, one of the most common types of bombs police encounter

– A pipe bomb consists of a short piece of pipe, capped at both ends.

– The pipe is filled with the powder and sometimes a stick of dynamite to shatter the pipe.


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TYPES OF BOMBS• Firebombs– Molotov cocktail

• Letter and Package Bombs– Not common– Package bombs vary widely in size, weight, shape, and the

color of the wrappings.– Some package bombs operate like letter bombs, with

pressure-release mechanisms. – Others contain a spring detonating device, held under

tension by the package’s sealing tape or string. – When the package is opened and the tape or string cut, the

spring is released and detonates the bomb.• Postal inspectors collaborate with federal, state, and local

authorities in investigating actual and threatened mail bombs.


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Letter and Package Bomb

Indicators


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Booby Trap Bombs

• Criminals use bombs as booby traps. • The explosion warns the criminal that intruders

are near and slows their entry, allowing an escape.

• Detonation of a booby trap bomb may be manual, remote, or timed, or the bomb may be set off by the victim through a hidden trip wire, pressure spring, or plate.


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INVESTIGATING BOMBING INCIDENTS

• Bomb threat cards– Operating

procedures generally should take into account the various skill levels of personnel involved in a bomb incident response.


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Searching for Bombs

• Bomb searches are typically conducted by two-person teams.

• Bombs are often equipped with clockwork timing devices, the sound of which may offer a clue to the explosive’s location.

• Untrained officers should make no effort to move, remove, or in any way jar a suspicious object.


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Disposing of an Unexploded Bomb• Move people away from the suspected bomb area, not moving

the suspected bomb away from the people.• Immediately notify qualified bomb disposal personnel, who can

evaluate the suspected bomb and take necessary actions.• Clear the danger area of all occupants to ensure as much safety

as possible. A simple ruse, such as a possible gas leak, may be used as an excuse to evacuate a building without causing panic from fear of a bomb.

• Create a clear zone with a perimeter at least 300 feet from the explosive device, and establish a guard to prevent reentry.

• Alert fire department, rescue, and medical emergency units.


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Disposing of an Unexploded Bomb• Protect and preserve the scene so that all possible physical

evidence can be obtained.• Note whether the package or object is ticking or making any

other audible noise.• Without touching the object, observe whether it appears to be

attached to anything or fastened down. Notify the bomb disposal team about these observations.

• If deemed advisable, remove any flammable materials from the immediate area of the suspected bomb to reduce injury or damage should an explosion occur.

• Shut off power, gas, and fuel lines leading into the danger area if the type of bomb warrants this action. Such action could prevent additional explosions that might add to the damage.


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Disposing of an Unexploded Bomb• Set up surveillance of the crowd of spectators to identify

possible suspects.• Photograph or videotape the crowd to possibly reveal

familiar faces that have appeared at other bombing sites.• Interview the person who

discovered the suspected bomb. • Likewise, interview anyone else at

the scene at the time regarding the possible identity of the bomber.


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Investigating an Exploded Bomb

• The primary objectives of an investigation following the explosion of a bomb are to:

Establish the nature of the bomb, Discover the method of ignition, and Obtain any other evidence that may assist in identification

and apprehension of the person or persons responsible.

• Seat of the blast– The primary location where an explosive has detonated.

• An explosion will leave a large crater


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Investigating an Exploded Bomb

• Search for forensic evidence, the first half inch of soil or debris from the seat of the blast should be collected for analysis.

• Soft materials often attract explosive residue and under analysis may assist in determining what type of explosives were used.

• Large immovable objects can be wiped with a cotton swab moistened with acetone to collect trace evidence of explosives.

• Investigative procedures (see pages 384-384)


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SUICIDE BOMBINGS

• Suicide bombers have become today’s weapon of choice for a number of terrorist organizations.

• Suicide bombers are the most feared weapons in the arsenal of modern-day political activists.

• The Shi’ia Amal group, introduced this tactic in Beirut in 1983.


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What Is a Suicide Bomber?

• Suicide bomber– An individuals who, using either a vehicle, aircraft,

or a selfcontained explosive device on his or her person or carried by this individual, detonates the device among a group of people or crashes the vehicle or aircraft into a building, structure, or populated area.

– Suicide bomber is an intentionally emotionally laden term.

– Groups using this tactic want to make martyrs of the perpetrators.


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What Is a Suicide Bomber?

• Homicide bomber in an effort to emphasize the criminal homicides that were being perpetrated and to de-emphasize the individuals as martyrs for their cause.


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Suicide Boming Incident Response

• If a suspected suicide bomber is identified in some location, law enforcement should take a series of actions.– Immediate notification– Containment of the bomber– Maintain standoff distance– Define the circumstances when lethal force is

justified– If lethal force is used, aim for the head– Radio frequency suppression and predetonation

Arson and Bombing Investigations Chapter 18. Copyright ©2008 The McGraw-Hill Companies, Inc. All...

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Transcript of Arson and Bombing Investigations Chapter 18. Copyright ©2008 The McGraw-Hill Companies, Inc. All...