Arson Awareness Fire Scene Preservation

City of Oswego Fire Department

Objectives

 Identify and describe the importance of observations made prior to, during or after a fire  Describe the importance of preserving a fire scene for cause determination.

 Describe methods of preserving fire scene evidence.

City of Oswego Fire Department

Fire Behavior

 Fire behavior is predictable.  A normal fire follows a predictable path of fire progression.  Growth Stage  Free Burning  Decay City of Oswego Fire Department

Fire Behavior

 Normal Fire Patterns  One ignition source  Growth is upward and outward  ‘V’ patterns form City of Oswego Fire Department

Fire Behavior

 Abnormal fire growth or burn patterns may indicate non-accidental cause:  Unusually heavy destruction in area of origin.

 Inverted ‘V’ patterns  Multiple areas of origin. City of Oswego Fire Department

Observation Skills

 Cause determination is based on various types of evidence.

 Burn patterns  Point of origin  Elimination of causes  Witness interviews – Occupants – Bystanders – Firefighters City of Oswego Fire Department

Observation Skills

 Firefighters are primary witnesses to the event, before, during and after the incident  Their observations can assist the efforts of investigators immensely.

 Firefighters should be prepared to provide written witness statements after the fire.

 Their ability to preserve evidence for investigators is crucial to cause determination.

City of Oswego Fire Department

Environmental Observations

 Wind direction and speed  Weather conditions  Neighborhood conditions  Real estate values  For sale signs  Problem areas City of Oswego Fire Department

Observations Enroute

 Note fire conditions reported from dispatch.

 Vehicles or people leaving the scene  Normally people move toward the fire  Unusual circumstances or obstacles  Blocked access City of Oswego Fire Department

Observations at the Scene

 Note time and fire conditions on arrival  Occupants clothing  Occupants behavior  Over curious  Indifferent  Too helpful  Bystanders (familiar faces?)  Location of fire City of Oswego Fire Department

Observations at the Scene

 Smoke color  May indicate what is burning.

 May indicate the stage of the fire  Fire travel  Unusual signs or routes of fire extension.

 Rate of Combustion City of Oswego Fire Department

Observations at the Scene

 Exterior evidence  Tracks  Flammable liquid containers  Greatest damage may help locate area of origin  Area of origin  Follow damage from least burned area to the area of greatest damage.

 Is ignition source readily identifiable?

City of Oswego Fire Department

Observations at the Scene

 Means of Entry  Were doors locked or unlocked?

 Signs of force entry prior to arrival.

 Condition of Windows  Open or closed.

 Shades up or down  Broken – Is the glass inside or out – Smoke stained or not City of Oswego Fire Department

Observations at the Scene

 Unusual odors  Petroleum or solvents  May prompt the taking of samples  Any containers on site, inside or out?

 Difficulty of extinguishment  Did fire react normally when water was applied  Did fire reignite or flash back City of Oswego Fire Department

Observations at the Scene

 Room Arrangement  Furnishings in place or absent  Correct items in the room  Do items appear to be substitutes?

 Signs of burglary   Are valuables missing What’s burning?

 Can object be identified.

 If not, eliminate other causes City of Oswego Fire Department

Observations on Arrival

 Signs of fire spread by unusual methods:  Trailers  Out of place fuel sources.

 Splash or pour patterns  Inverted ‘V’ or cone patterns  Did fire protection work?

 Detection systems  Suppression systems  Did system control fire? If not, why not?

City of Oswego Fire Department

Observations at the Scene

 Incendiary devices:  Trailers  Fusees  Match books  Hypergolic chemical mixtures City of Oswego Fire Department

City of Oswego Fire Department

Observations on Arrival

 Depth of charring  Depends on type of wood and length of burn  May help indicate area of orign  May help determine length of time fire burned  Spalling  Annealing of springs  Beading on wiring City of Oswego Fire Department

Observations on Arrival

 Burn Patterns:  ‘V’  Inverted ‘V’  Truncated cone  Hour glass  Lines of demarcation  Clean burn  Staining of glass City of Oswego Fire Department

City of Oswego Fire Department

‘V’ Patttern

Origin and Cause often found at apex of ‘V’

City of Oswego Fire Department

Area of Origin

City of Oswego Fire Department

Point of Origin/ Source of Ignition

City of Oswego Fire Department

Line of Demarcation

City of Oswego Fire Department

Clean Burn

City of Oswego Fire Department

Observations on Arrival

 Separate fires  May be caused by dropdown  May be evidence of set  Means of Entry  Doors locked or unlocked  Signs of forced entry prior to arrival City of Oswego Fire Department

City of Oswego Fire Department

City of Oswego Fire Department

Observations on Arrival

 Indicators of the direction of fire spread  There may be more than one ‘V’ pattern – Look for lowest burn  Melted glass and light bulbs.

 Different degrees of charring on furnishings City of Oswego Fire Department

Preserving Evidence

 The entire fire scene is of evidentiary value, not just the apparent area of origin.

 Overhaul is a destructive, but necessary phase of fire suppression.

 Opening voids to check for extension.

 Pulling appliances away from walls  Opening furniture cushions, bedding and mattress to eliminate deep seated fire.

 All of these activities may destroy evidence.

City of Oswego Fire Department

Preserving Evidence

 When conducting overhaul, be able to recognize evidence which may be of use to investigators.

 Delay overhaul, if possible, until a fire investigator can assess the scene.

 If overhaul cannot be delayed, attempt to keep damage to a minimum, and report observations to investigator ASAP.

City of Oswego Fire Department

Preserving Evidence

 Attempt to preserve fire patterns and other physical evidence during overhaul.

 Inspection holes  Leave furniture in place or return to original position.

 Minimize water damage.

 Limit number of personnel in area.

City of Oswego Fire Department

Preserving Evidence

 NEVER move or dismantle evidence.

 Destruction of context  Spoliation City of Oswego Fire Department