More informative DNA identification:Computer reinterpretation of existing dataRia David, PhDRia David, PhDCybergenetics, Pittsburgh, PACybergenetics, Pittsburgh, PACybergenetics 2003-2010Cybergenetics 2003-2010Midwestern Association of Forensic Midwestern Association of Forensic Scientists 39th Annual MeetingScientists 39th Annual MeetingOctober, 2010October, 2010SWGDAM 2010 SWDGAM guidelines, section 3.2.2If a stochastic threshold based on peak height is not used in the evaluation of DNA typing results, the laboratory must establish alternative criteria (e.g., quantitation values or use of a probabilistic genotype approach) for addressing potential stochastic amplification. The criteria must be supported by empirical data and internal validation and must be documented in the standard operating procedures. TrueAllele CaseworkComputer interpretation of DNA evidenceComputer interpretation of DNA evidenceby mathematically modeling STR processby mathematically modeling STR process objectivity objectivity ease of use ease of use information information productivity productivityPrimary goalsPrimary goalsInterpretation MattersNational Institute of Standards and TechnologyTwo Contributor Mixture Data, Known Victim31 thousand (4)213 trillion (14)Preserving DNA Information Quantitative vs. QualitativePreserving DNA Information Quantitative vs. QualitativeData ClassificationMixture items assigned a degree of difficultySimple: two person mixture with a known victim Medium: two unknown mixture samplesComplex: three or more unknown contributors, or a partial profile Information - two unknown 7.03 7.03 6.24 6.2413.2613.26Information - all mixturesLocus D21S11Quantitative TrueAlleleQuantitative TrueAlleleQuantitative TrueAlleleQuantitative TrueAlleleQuantitative TrueAlleleQualitative ThresholdQualitative ThresholdQualitative ThresholdQualitative ThresholdQualitative ThresholdStochastic ThresholdStochastic ThresholdStochastic ThresholdStochastic Threshold13 Locus StatisticConclusion Forensic analysts goal is to get identification information from their data to help solve cases SWGDAM guidelines make it more difficult for analysts to extract information from DNA data TrueAlleles approach of probabilistic interpretation is allowed by the SWGDAM guidelines and extracts more identification information than human interpretation Using a probabilistic genotype interpretation would enable forensic analysts to better ensure public safety AcknowledgementsNew York State PoliceBarry DucemanMelissa LeeShannon MorrisElizabeth StaudeCybergeneticsWilliam AllanMeredith ClarkeMatthew LeglerJessica SmithCara SpencerNortheast RegionalForensics InstituteJamie Belrose