Simple Reporting of Simple Reporting of Complex DNA Evidence: Complex DNA Evidence:
Automated Computer InterpretationAutomated Computer Interpretation
Promega 14th International SymposiumPromega 14th International Symposiumon Human Identificationon Human Identification
Pointe Hilton Tapatio Cliffs ResortPointe Hilton Tapatio Cliffs ResortPhoenix, AZPhoenix, AZ
October, 2003October, 2003
Single source:Single source:Peak Peak allele. allele.At locus,At locus,report thereport thegenotype. genotype.
Data Issues:Data Issues:Peak height/areaPeak height/areaPeak sizePeak sizePCR stutterPCR stutterPref ampPref ampMixed samplesMixed samplesLow amountsLow amountsDegraded DNADegraded DNAMany samplesMany samplesMany contributorsMany contributorsContributor countContributor countBackground noiseBackground noiseRandom variationRandom variationLCN PCRLCN PCR
Math/stat models:Math/stat models:Peak height/areaPeak height/areaPeak sizePeak sizePCR stutterPCR stutterPref ampPref ampMixed samplesMixed samplesLow amountsLow amountsDegraded DNADegraded DNAMany samplesMany samplesMany contributorsMany contributorsContributor countContributor countBackground noiseBackground noiseRandom variationRandom variationLCN PCRLCN PCR
Single source:Single source:Peak Peak allele. allele.At locus,At locus,for contributor,for contributor,report thereport thegenotype(s). genotype(s).
Recent RevolutionsRecent Revolutions
• • science science PCR, sequencerPCR, sequencer
• • technologytechnologycomputercomputer
• • lawlawDaubertDaubert
• • statisticsstatisticscomputational truthcomputational truth
TrueAllele™TrueAllele™
Expert systemExpert systema computer program thata computer program thatreplicates human expertisereplicates human expertise
HistoryHistory
System: System: 2 2 3 3Version: Version: 14 14 15 15
Admissibility Admissibility
Rule 702Rule 7021.1. DataData2.2. MethodMethod3.3. ApplicationApplication
DaubertDaubert1.1. TestableTestable2.2. Error rateError rate3.3. Peer reviewPeer review4.4. General acceptanceGeneral acceptance
Validation DesignValidation Design
10%10%30%30%50%50%70%70%90%90%
1, 1/2, 1/4, 1/8 ng1, 1/2, 1/4, 1/8 ng
STR Data GenerationSTR Data Generation
• • premixed DNA templates: premixed DNA templates: NISTNIST• • lab protocols: lab protocols: CybergeneticsCybergenetics• • data generation (ten DNA labs)data generation (ten DNA labs) Florida, New York, Ohio, Pennsylvania, Florida, New York, Ohio, Pennsylvania, Virginia, Cellmark, UK FSS, CybergeneticsVirginia, Cellmark, UK FSS, Cybergenetics• • DNA sequencers:DNA sequencers: FMBio/II, 377, 310, 3100, 3700FMBio/II, 377, 310, 3100, 3700• • STR panels: STR panels: PowerPlex (1, 2, 16), PowerPlex (1, 2, 16), ProfilerPlus, Cofiler, SGMplus, IdentifilerProfilerPlus, Cofiler, SGMplus, Identifiler
Data AnalysisData AnalysisTrueAllele™ AutomationTrueAllele™ Automation
sequencersequencerdata filedata file
peak height databasepeak height database
analysisanalysis
Case InterpretationCase InterpretationTrueAllele™ AutomationTrueAllele™ Automation
sequencersequencerdata filedata file
peak height databasepeak height database
reportreport
analysisanalysis
interpretationinterpretation
No Suspect ExampleNo Suspect Example
ContributorsContributorsA: VictimA: Victim
G: Unknown SuspectG: Unknown Suspect
SamplesSamplesA1 (Victim)A1 (Victim)
C1 (Mixture) C1 (Mixture) 70% A 70% A ++ 30% G30% G
1 ng DNA, PowerPlex16, ABI/3101 ng DNA, PowerPlex16, ABI/310
Simplicity GoalsSimplicity Goals
• • time time < 1 minute< 1 minute• • information information full powerfull power• • understandable understandable yesyes• • admissible admissible yesyes
1,440 minutes each day1,440 minutes each dayBacklog?Backlog?(no suspect, convicted offender)(no suspect, convicted offender)
10 11 12
ConservativeConservative ExactExact101010111112
101112111212
10 12CautiousCautious101112
121212
Discriminating PowerDiscriminating Power
26/2626/26 18/2618/263.6x103.6x101616 6.1x106.1x101111
Concordance: DPConcordance: DPSynthetic: NIJ study comparisonsSynthetic: NIJ study comparisonsCases: 1,000 no suspect rape kitsCases: 1,000 no suspect rape kits
Lab Process ScenariosLab Process Scenarios• • screen data, organize casescreen data, organize case• • second scorer reviewsecond scorer review• • post-conviction DNA testingpost-conviction DNA testing• • service for DNA analystservice for DNA analyst• • NDIS forensic uploadNDIS forensic upload• • NDIS profile downloadNDIS profile download• • mass disastersmass disasters• • serial crimeserial crime• • advance troubleshootingadvance troubleshooting• …• …
ConclusionsConclusions
• • timetime• • informationinformation• • understandableunderstandable• • admissibleadmissible
casework interpretation systemcasework interpretation system: : objective, unbiased, reproducible, objective, unbiased, reproducible, reliable, admissible, availablereliable, admissible, availablereportsreports:: simple, understandable simple, understandablestudiesstudies:: concordance, validation concordance, validation
AcknowledgementsAcknowledgementsNational Institute of Justice: National Institute of Justice: Award #2001-IJ-CX-K003Award #2001-IJ-CX-K003
Collaborators at: Collaborators at: Florida, New York, Ohio, Pennsylvania, Florida, New York, Ohio, Pennsylvania, Virginia, NIST, Cellmark, UK FSSVirginia, NIST, Cellmark, UK FSS
Cybergenetics: Cybergenetics: Developers, Quality Process, DNA LabDevelopers, Quality Process, DNA Lab
[email protected]@cybgen.com