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CHEMICAL ENHANCEMENT OF FINGERPRINTS IN BLOOD AN EVALUATION OF METHODS DR. J.D. DEHAAN J.D. CLARK T.F. SPEAR S.S. BARNEY.

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Presentation on theme: "CHEMICAL ENHANCEMENT OF FINGERPRINTS IN BLOOD AN EVALUATION OF METHODS DR. J.D. DEHAAN J.D. CLARK T.F. SPEAR S.S. BARNEY."— Presentation transcript:

1 CHEMICAL ENHANCEMENT OF FINGERPRINTS IN BLOOD AN EVALUATION OF METHODS DR. J.D. DEHAAN J.D. CLARK T.F. SPEAR S.S. BARNEY

2 PHOTOGRAPHY WAS THE ONLY METHOD TO ENHANCE BLOODY IMPRESSIONS BEFORE BEFORE AFTER

3 AMIDO BLACK WAS USED TO CHEMICALLY ENHANCE THE BLOODY FINGERPRINT BEFORE BEFORE AFTER

4 AND THE BLOODY SHOE PRINT BEFORE BEFORE AFTER

5 REAGENTS WERE EVALUATED THAT COULD CHANGE THE COLOR OR FLUORESCE THE BLOOD COLOR CHANGE COLOR CHANGE AMIDO BLACK AMIDO BLACK NINHYDRIN NINHYDRIN LEUCO CRYSTAL VIOLET LEUCO CRYSTAL VIOLET FLUORESCENCE FLUORESCIN MERBROMIN DFO (Initial tests confirmed published reports that the absorption of the blood quenched the fluorescence of DFO. No further study was done with DFO)

6 REAGENTS WERE EVALUATED FOR THE FOLLOWING SENSITIVITY SENSITIVITY EFFECTS OF THE SUBSTRATE EFFECTS OF THE SUBSTRATE EFFECTS OF TIME EFFECTS OF TIME FLUORESCING CAPABILITIES FLUORESCING CAPABILITIES EDGE DETAIL AFTER PROCESSING EDGE DETAIL AFTER PROCESSING IMPACT ON DNA ANALYSIS IMPACT ON DNA ANALYSIS

7 SENSITIVITY WAS MEASURED BY SEQUENTIAL TOUCHES OF FINGERS MOISTENED WITH HUMAN BLOOD

8 ALSO BY SERIAL DILUTION

9 DUE TO THE TIME REQUIRED FOR NINHYDRIN TO REACT, IT WAS NOT CONDUCIVE FOR USE IN THE FIELD AND STUDY WAS LIMITED TO ONLY SERIAL DILUTION TARGETS USED FOR COLOR AMIDO BLACK AMIDO BLACK LEUCO CRYSTAL VIOLET

10 POROUS TARGETS WERE IMPACTED BY AMIDO BLACK WHILE LEUCO CRYSTAL VIOLET WAS NOT AMIDO BLACK LEUCO CRYSTAL VIOLET AMIDO BLACK LEUCO CRYSTAL VIOLET

11 LEUCO CRYSTAL VIOLET OXIDIZES BY LIGHT AND TIME FORMING BACKGROUND COLOR OXIDATION CAN BE REDUCED BY RINSING WITH DISTILLED WATER AFTER REAGENT APPLICATION OXIDATION CAN BE REDUCED BY RINSING WITH DISTILLED WATER AFTER REAGENT APPLICATION

12 SERIAL DILUTION FLUORESCENT CAPABILITY TESTS DISCOVERED THAT LEUCO CRYSTAL VIOLET FLUORESCED AT 532nm

13 THE THICKENER USED IN FLUORESCIN IMPACTED EXTRACTING DNA. THE THICKENER WAS REMOVED FROM THE FORMULA FOR THIS TEST. NO EDGE DETAIL NO EDGE DETAIL EVEN WITH FINE MISTING

14 MERBROMIN HELD THE EDGE DETAIL WELL EVEN WITH HEAVY APPLICATION THE SAME OXIDATION OCCURES WITH MERBROMIN. MINIMIZE OXIDATION WITH A DISTILLED WATER RINSE

15 LEUCO CRYSTAL VIOLET IS VERY EFFECTIVE ON SHOE PRINTS BEFORE BEFORE AFTER

16 FLUORESCING IMPRESSIONS LEUCO CRYSTAL VIOLET LEUCO CRYSTAL VIOLET MERBROMIN

17 IMPACT ON DNA ANALYSIS 14 PCR MARKERS WERE SUCCESSFULLY TYPED WITH THE 6 TESTED REAGENTS

18 SAFETY Sr. Industrial Hygienist Rod Oswalt of the Calif. Criminalistics Institute Prepared A Hazard Assessment On Merbromin and Leuco Crystal Violet (LCV) The Hazards Of Mercury Is Well Known. Due to Mercury Being the Primary Reagent in Merbromin, It’s Use Should Be Limited To a Laboratory Vent Hood. The Published Articles Listed LCV As Relatively Safe With Moderate Caution. The Three Main Exposure Pathways Of Inhalation, Skin Absorption and Ingestion Are Viable Routes By The Application Methods. “LCV Is An Analogue Of The Aniline Compounds And Benzidine-Based Dyes, And The Body Will Readily Absorb LCV. Further, Many Of The Benzidine- Based Dyes Are Metabolized By The Human Body Into Benzidine, Which Is Known To Cause Cancer. It Is Unclear Based Upon Available Information, Whether LCV/CV is Metabolized Via That Pathway.”

19 CONCLUSIONS LIGHT COLOR TARGETS POROUS POROUS LEUCO CRYSTAL VIOLET (No background staining) LEUCO CRYSTAL VIOLET (No background staining) NON-POROUS AMIDO BLACK (10 Times more sensitive than LCV) LEUCO CRYSTAL VIOLET (Hemoglobin Specific)

20 CONCLUSIONS DARK COLOR TARGETS POROUS POROUS MERBROMIN (Fluoresces with many wave lengths) MERBROMIN (Fluoresces with many wave lengths) NON-POROUS MERBROMIN (Fluoresces with many wave lengths)


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