Presentation on theme: "Sarah Kunkel 2006 MAAFS Annual Meeting May 5, 2006"— Presentation transcript:
1Sarah Kunkel 2006 MAAFS Annual Meeting May 5, 2006 The Limitations and Advantages of Ultraviolet Light Sources in the Detection of Ignitable Liquids at Fire ScenesSarah Kunkel2006 MAAFS Annual MeetingMay 5, 2006
2UV in Arson Investigation Ultra violet lights marketed to arson investigators for decadesVery few reliable studies to support their claims
3Ultraviolet Light Test Objectives Determine capabilities of UV light sourceDetermine limitations of UV light sourceDetermine whether UV light source is a practical approach to ignitable liquids detection at fire scenes
4Ultraviolet Light Source Model UVSL-26P by UVP in CaliforniaRechargeableThree modes of operationShort wave (254nm)Long Wave (365nm)Dual
5Testing Performed Amount of Ignitable Liquid Time Exposure Visualization of Various Ignitable LiquidsVisualization on Various MaterialsVisualization on Various Burnt Materials
6I. Amount of Ignitable Liquid All amounts of gasoline tested on carpet and asphalt tile10 μL25 μL50 μL100 μL150 μL300 μLgiving a nonporous and porous surface
7I. Amount of Ignitable Liquid All amounts detectable on carpet and asphalt tile50 μL gasoline on asphalt tile50 μL gasoline on carpet
8I. Amount of Ignitable Liquid 10 μL gasoline on carpet10 μL gasoline on asphalt tile300 μL gasoline on asphalt tile300 μL gasoline on carpet
9I. Amount of Ignitable Liquid Close-up:10 μL gasoline on carpet
10II. Time Exposure All tested on carpet and asphalt tile 30 minutes Extended to 1 month of viewing (when research ended) and no change in visualization
11II. Time ExposureAll amounts detectable on the tile and carpet at 10 months50 μL gasoline on asphalt tile10 months later1st Day
12III. Ignitable Liquids Tested All liquids tested at 10 μL and 50 μL on asphalt tileIgnitable liquids tested:Gasoline (Unevaporated, 50%, 75%, and 90% evaporated, and Base)Diesel fuelLighter fluidLinseed oilVarious ignitable liquids used to calibrate the canine detection team
13III. Ignitable Liquids Tested Only gasoline, diesel fuel, and linseed oil detectable on all material at all amountsWeathered gasoline fluoresces brighter than non-weathered90%>75%>50%>non-weatheredBase gasoline not detectableGasoline from various companies indistinguishable
15IV. Flooring Materials Tested CarpetLinoleumFoam Carpet PaddingFiber Filled Carpet PaddingAsphalt TileWood FlooringThese materials were also burned and used for the burnt vs. unburnt portion of the experiment.
16IV. Other Materials Tested 100% White Cotton T-shirtJeansHuman SkinManila FolderWhite Printer PaperWhite Notebook PaperYellow Notebook PaperPaper Towel
17IV. Flooring Materials Tested Must use only short wavelength on linoleumCarpet and asphalt tile worked under long, short, and dual wavelengthMostly questionable positives for fiber filled carpet padding and wood flooringDiesel fuel absorbed light on short wave for jean and t-shirt
18IV. Other Materials Tested Negative results on jeans and cotton t-shirtSkinRemain detectable on skin between 8-9 hoursCanine team did not detect after 3 hoursFluoresced after 5 hand washingsPaper productsBoth liquids fluoresced on all paper productsLight absorbed when liquid was still wet
19V. Burnt Materials Tested CarpetLinoleumFoam Carpet PaddingFiber Filled Carpet PaddingAsphalt TileWood FlooringThese materials were also burned and used for the burnt vs. unburnt portion of the experiment.
21V. Burnt Materials Tested Only short and dual wavelengths visualized the ignitable liquidsGasoline less visible than diesel fuel on all materialsResults varied from unburned materialsLess positive resultsCarpet absorbed lightLess pos – especially asphalt tile and wood flooring
22Additional ResultsDawn detergent masks ignitable liquids from the canine teams but no affect on fluorescenceExposure to water does not affect fluorescenceSubmerged in water for 24 hours
23ConclusionsUV light only useful in detection of gasoline and diesel fuelNot affected by water, but burning of material does affect visibilityUseful with small volumes and at long exposure timesFluorescence caused by dyes in ignitable liquids
24Acknowledgements Don Brucker, Allegheny County Fire Marshal’s Office Bob Huston, Allegheny County Crime LaboratoryDr. Graham Rankin, Marshall University
25ReferencesDeHaan, J. D. Kirk’s Fire Investigation 4th edition. Prentice Hall,Forestal, R. Use of Ultraviolet Light in Fire/Arson, Bomb, and Environmental Investigation. Firehouse Magazine September 1994: 48-50Brucker, D. Chief Deputy Fire Marshal, Allegheny County Emergency Services. July 18-27, Pittsburgh, Pennsylvania.U.S. Fire Administration. Arson in the United States (Topical Fire Research Series). The Administration. January (8): 1-3Ultra-Violet Products. Use of Ultraviolet Light in Arson Detection [Application Bulletin-UVP-AB-107]. 1997Stauffer, Eric. Technical Working Group for Fire and Explosives Discussion. March 21, 2006.