ARSON DETECTION Arson = crime of intentionally starting a fire that damages property Difficult to prove - fire or firefighters destroy evidence - combustible liquids (accelerants) evaporate quickly Types of Fires CategoryDescription Natural Accidental Undetermined Deliberate Types of Fires CategoryDescription NaturalCaused by acts of nature; ex. Lightening strike Accidental Undetermined Deliberate Types of Fires CategoryDescription NaturalCaused by acts of nature; ex. Lightening strike AccidentalUnintentional & explainable; ex. Faulty wiring, carelessness Undetermined Deliberate Types of Fires CategoryDescription NaturalCaused by acts of nature; ex. Lightening strike AccidentalUnintentional & explainable; ex. Faulty wiring, carelessness UndeterminedCause unknown & cant be identified Deliberate Types of Fires CategoryDescription NaturalCaused by acts of nature; ex. Lightening strike AccidentalUnintentional & explainable; ex. Faulty wiring, carelessness UndeterminedCause unknown & cant be identified Deliberate Intentionally set may or may not be arson; ex. Campfire spreads out of control Burn Patterns PatternDescriptionIndication V-shape Burn Patterns PatternDescriptionIndication V-shapeNarrow at bottom, spreads out as rises Normal pattern, no accelerant Burn Patterns PatternDescriptionIndication V-shapeNarrow at bottom, spreads out as rises Normal pattern, no accelerant Inverted cone Burn Patterns PatternDescriptionIndication V-shapeNarrow at bottom, spreads out as rises Normal pattern, no accelerant Inverted coneWider at bottom, narrower upMay be accident or accelerant poured along floor Burn Patterns PatternDescriptionIndication V-shapeNarrow at bottom, spreads out as rises Normal pattern, no accelerant Inverted coneWider at bottom, narrower upMay be accident or accelerant poured along floor Alligatoring Burn Patterns PatternDescriptionIndication V-shapeNarrow at bottom, spreads out as rises Normal pattern, no accelerant Inverted coneWider at bottom, narrower upMay be accident or accelerant poured along floor AlligatoringLooks like scales of alligatorMay be from accelerant, maybe not Burn Patterns PatternDescriptionIndication V-shapeNarrow at bottom, spreads out as rises Normal pattern, no accelerant Inverted coneWider at bottom, narrower upMay be accident or accelerant poured along floor AlligatoringLooks like scales of alligatorMay be from accelerant, maybe not Spalling Burn Patterns PatternDescriptionIndication V-shapeNarrow at bottom, spreads out as rises Normal pattern, no accelerant Inverted coneWider at bottom, narrower upMay be accident or accelerant poured along floor AlligatoringLooks like scales of alligatorMay be from accelerant, maybe not SpallingLayers of concrete break away b/c of high temps May be from accelerant, maybe not Burn Patterns PatternDescriptionIndication V-shapeNarrow at bottom, spreads out as rises Normal pattern, no accelerant Inverted coneWider at bottom, narrower upMay be accident or accelerant poured along floor AlligatoringLooks like scales of alligatorMay be from accelerant, maybe not SpallingLayers of concrete break away b/c of high temps May be from accelerant, maybe not Streamers Burn Patterns PatternDescriptionIndication V-shapeNarrow at bottom, spreads out as rises Normal pattern, no accelerant Inverted coneWider at bottom, narrower upMay be accident or accelerant poured along floor AlligatoringLooks like scales of alligatorMay be from accelerant, maybe not SpallingLayers of concrete break away b/c of high temps May be from accelerant, maybe not StreamersShows a trail from one area to another Accelerant used to spread fire Burn Patterns PatternDescriptionIndication V-shapeNarrow at bottom, spreads out as rises Normal pattern, no accelerant Inverted coneWider at bottom, narrower upMay be accident or accelerant poured along floor AlligatoringLooks like scales of alligatorMay be from accelerant, maybe not SpallingLayers of concrete break away b/c of high temps May be from accelerant, maybe not StreamersShows a trail from one area to another Accelerant used to spread fire Arc damage Burn Patterns PatternDescriptionIndication V-shapeNarrow at bottom, spreads out as rises Normal pattern, no accelerant Inverted coneWider at bottom, narrower upMay be accident or accelerant poured along floor AlligatoringLooks like scales of alligatorMay be from accelerant, maybe not SpallingLayers of concrete break away b/c of high temps May be from accelerant, maybe not StreamersShows a trail from one area to another Accelerant used to spread fire Arc damageSpark caused by release of electricity Electrical wire; or from wire insulation Burn Patterns PatternDescriptionIndication V-shapeNarrow at bottom, spreads out as rises Normal pattern, no accelerant Inverted coneWider at bottom, narrower upMay be accident or accelerant poured along floor AlligatoringLooks like scales of alligatorMay be from accelerant, maybe not SpallingLayers of concrete break away b/c of high temps May be from accelerant, maybe not StreamersShows a trail from one area to another Accelerant used to spread fire Arc damageSpark caused by release of electricity Electrical wire; or from wire insulation Pool or plant Burn Patterns PatternDescriptionIndication V-shapeNarrow at bottom, spreads out as rises Normal pattern, no accelerant Inverted coneWider at bottom, narrower upMay be accident or accelerant poured along floor AlligatoringLooks like scales of alligatorMay be from accelerant, maybe not SpallingLayers of concrete break away b/c of high temps May be from accelerant, maybe not StreamersShows a trail from one area to another Accelerant used to spread fire Arc damageSpark caused by release of electricity Electrical wire; or from wire insulation Pool or plantLook like puddlesAccelerants collected in a pool at lowest point