Simple Reporting of Complex DNA Evidence: Automated Computer Interpretation

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

perlin@cybgen.comperlin@cybgen.com