Arson - Forensics

Where did Julio get the accelerant? What was suspicious about him?

Local gas station His home & shoes smelled of gasoline

Vaporization

Liquid changes to gas

Direct extraction procedure (2)

1) Remove vapors w/ syringe 2) Analyze vapors w/ gas chromatography

Psychology of an arsonist (3)

1) Sense of power 2) Emotional high 3) No typical arsonist. Only possible characteristics

How should fire evidence be collected? (4)

1) Begin immediately; no warrant needed 2) Collect 3-4 liters of ash from point of origin & other suspected areas 3) Use portable vapor detectors (sniffers) 4) Use trained dogs to sniff

What is the function of a fire investigator? (4)

1) Collect evidence quickly before it's lost 2) Find fire's point of origin 3) Examine possible causes (accidental vs. arson) 4) Classify fire

What three things does combustion involve?

1) Combustion reactions 2) Heat of combustion 3) Exothermic reactions

Why is arson difficult to prove? (4)

1) Crime usually carefully planned 2) Fire destroys evidence 3) Arsonist leaves scene before anyone notices fire 4) Extinguishing the fire also destroys evidence

Six motives for arson

1) Financial gain (insurance fraud) 2) Revenge, spite 3) Excitement 4) Vanity, hero syndrome 5) Crime concealment (destroy evidence) 6) Vandalism

What are the four igniters (causes of fires)?

1) Matches 2) Cigarette lighters 3) Molotov cocktails 4) Faulty electrical wiring

List fire classifications (4)

1) Natural 2) Accidental 3) Undetermined 4) Deliberate

Parts of the fire tetrahedron (what's needed to start a fire & keep it burning)

1) Oxygen 2) Fuel 3) Heat 4) Chain reaction

How should the fire control sample be collected? (4)

1) Place each sample in its own container 2) Collect a substrate control 3) Comparisons to the substrate control can help prove an accelerant was used 4) Some products may look like accelerants when burned

Passive extraction procedure (4)

1) Suspend a charcoal-coated strip inside can 2) Replace lid 3) Heat container 4-16 hrs at 50-80 deg. C 4) Charcoal absorbs the vapor

How should debris be packaged? (2)

1) Use airtight containers like a new, clean, paint can & lid 2)Leave head space at top of can

How many people were trapped and died?

87 of the 90

Fire (chemistry of it)

A rapid oxidation reaction that involves a combustible material

Substrate Control

A similar but uncontaminated sample Used for making comparisons

What does the streamers pattern indicate?

Accelerant was used to spread fire from one area to another

Faulty electrical wiring

An arc causes a predictable pattern

Hydrocarbon

Any compound consisting only of hydrogen & carbon

Accelerant

Any material used to start/sustain a fire. Most common is combustible liquids

Why did Julio set fire to the Happy Land Club in Bronx?

Because Lydia broke up with him

Spalling Pattern

Breaking away of layers of concrete due to exposure to high temperatures

Pool or plant Pattern

Burns in a puddle configuration

Classic V Pattern

Burns narrower at bottom, spreads outward as it rises.

Alligatoring Pattern

Burns resemble scales of an alligator

Streamers Pattern

Burns show a trail from one area to another

Inverted Cone Pattern

Burns wider along floor & narrower as it burns upward

Undetermined fires

Cause unknown & can't be identified

Natural fires

Caused by acts of nature (lightning strike, intense sunlight)

Exothermic Reaction

Chemical reaction that releases heat

What does an inverted cone indicate?

Could be caused by accident or by accelerant poured along floor

Pyrolysis

Decomposition of organic matter by heat in the absence of oxygen

What does arc damage indicate?

Electrical fire or a fire that's burned through wire insulation

Heat of combustion

Excess heat given off in a combustion reaction

Examples of hydrocarbons

Gasoline Kerosene lighter fluid

Deliberate fires

Intentionally set. Not all arson. Could be a campfire that spread out of control.

Who was primarily involved in the Happy Land Fire?

Julio Gonzalez and Lydia Feliciano

What are the possible characteristics of an arsonist? (11)

Less than 25 yrs Father gone Domineering mother Academically challenged Emotionally/psychologically disabled Unmarried Living w/ parents Inadequacy, insecurity Fascination w/ fire Alcoholism Parental neglect/abuse

Molotov cocktails

May leave glass fragments

What happens in a gas state?

Molecular bonding is weaker

What are most accelerants (concerning hydrogen & carbon)?

Most accelerants are hydrocarbons in a gas state

Matches

Often burns in fire Most common Don't leave much evidence of match used

Cigarette lighters

Often removed by arsonist

What does a Classic V pattern indicate?

Ordinary burn pattern No accelerant used

Combustion Reaction

Oxidation reaction involving oxygen Releases heat & light

What does a spalling pattern indicate?

Possible use of accelerant, but not absolute

What does alligatoring indicate?

Possible use of accelerant, but not absolute

What does a pool or plant pattern indicate?

Poured accelerants accumulated in a pool at the lowest point

Arc Damage Pattern

Spark caused by a release of electricity

Oxidation reaction

The complete or partial loss of electrons or gain of oxygen

Arson

The intentional & illegal burning of property

Flashpoint

The lowest temperature at which vaporization occurs in an accelerant

Accidental fires

Unintentional & explainable Caused by faulty wiring, malfunctioning appliance, human carelessness

Vapors and pyrolysis

Vapors given off from resins in wood are flammable and will burn