handling of the Brand o n Mavfield case Unclassified and redacted Retrieved

Handling of the brand o n mavfield case unclassified

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handling of the Brand o n Mavfield case: Unclassified and redacted. Retrieved March 15, 2007 from Office of the Inspector General Web site: EVIDENCE PRINT DAOUD PRINT 43 Office of the Inspector General, Oversight and Review Division (March 2006). A review o f the FBI's handling of the Brand o n Mavfield case: Unclassified and redacted. Retrieved March 15, 2007 from Office of the Inspector General Web site: MAYFIELD PRINT DAOUD PRINT 44 Research: Statistical 45 46 47 Fingerprint Admissibility? Questions of reliability? The problem with exclusion is that fingerprinting, although problematic, is still probably far more probative than much evidence that we do permit, both expert and nonexpert; so it seems somewhat perverse to exclude fingerprinting while permitting, say, eyewitness testimony. Jennifer L. Mnookin, Fingerprints: Not a Gold Standard, Issues in Science & Technology, October 2003. Cost to the justice system? Adversarial process In an enlightened environment, the use of experts for both sides should be able to draw out any uncertainties regarding the evidence. 48
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3/13/20 9 DEVELOPING LATENT PRINTS Techniques can be physical or chemical in nature. 49 Physical Methods Useful for prints on hard, non-absorbent surfaces Powder dusting (colored/fluorescent/ magnetic powders) Laser analysis (argon laser fluoresces print which is then photographed) X-ray analysis (electron emission radiography) Vacuum coating (deposition of a thin film of metal onto the print; used for prints on fabric, paper etc.) 50 Laser Fluorescence Riboflavin and pyridoxin are components of fingerprint residue which fluoresce. 51 Chemical Methods Usually required for prints on soft, porous surfaces Iodine fuming - detects fatty oils left behind in sweat; yellowish-brown prints observed are temporary Ninhydrin spraying - detects amino acids in sweat; purple-blue print formed; works well on old prints on paper Silver nitrate exposure - detects salt (chloride ion) in sweat; developed print is reddish brown AgNO 3 + NaCl → NaNO 3 + AgCl 2AgCl →2 Ag + Cl 2 Super Glue â fuming: cyanoacrylate; forms a white colored pattern 52 Iodine Fuming Left side: Iodine Right side: Iodine print fixed with benzoflavone 53 Ninhydrin Prints Jon T. Stimac, Oregon State Police Latent print developed with Ninhydrin in 3M™ Novec™ Engineered Fluid HFE-7100 (left) and Ninhydrin in Petroleum Ether (right) Ninhydrin Prints 54
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3/13/20 10 Cyanoacrylate Fuming 55
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