CHEMICAL ENHANCEMENT OF FINGERPRINTS IN BLOOD AN EVALUATION

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

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

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

AND THE BLOODY SHOE PRINT n BEFORE n AFTER

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

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

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

ALSO BY SERIAL DILUTION

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 n AMIDO BLACK n LEUCO CRYSTAL VIOLET

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

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

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

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

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

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

FLUORESCING IMPRESSIONS n LEUCO CRYSTAL VIOLET n MERBROMIN

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

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. ”

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

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