Upload File

gc×gc-ms and bayesian testing in forensics … · gc×gc-ms and bayesian testing in forensics ......

  • Home
  • Documents
  • GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon
21
GC×GC-MS AND BAYESIAN TESTING IN FORENSICS: TOWARDS THE IDENTIFICATION OF SUSPECTS THROUGH THEIR ODOR Isabelle RIVALS 1 , Vincent CUZUEL 2 , Guillaume COGNON 2 , Roman Lecon Didier THIEBAUT 3 , Charles SAULEAU 2 , Jérôme VIAL 3 – GCxGC 2018, Riva Del Garda, Italy Équipe de StaSsSque Appliquée, UMRS 1158, ESPCI Paris, France InsStut de Recherche Criminelle de la Gendarmerie NaSonale, Cergy-Pontoise, France UMR CBI 8231 - Laboratoire Sciences AnalySques, BioanalySques et MiniaturisaSon – ESPCI Paris – PSL Research University

Upload: hathuy

Post on 30-Jul-2019

227 views

Category:

Documents


0 download

Report

TRANSCRIPT

Page 1: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

GC×GC-MSANDBAYESIANTESTINGINFORENSICS:TOWARDSTHEIDENTIFICATIONOFSUSPECTSTHROUGH

THEIRODORIsabelleRIVALS1,VincentCUZUEL2,GuillaumeCOGNON2,RomanLeconte2

DidierTHIEBAUT3,CharlesSAULEAU2,JérômeVIAL3

ISCC–GCxGC2018,RivaDelGarda,Italy

1-ÉquipedeStaSsSqueAppliquée,UMRS1158,ESPCIParis,France2-InsStutdeRechercheCriminelledelaGendarmerieNaSonale,Cergy-Pontoise,France3-UMRCBI8231-LaboratoireSciencesAnalySques,BioanalySquesetMiniaturisaSon–ESPCIParis–PSLResearchUniversity

Page 2: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

CONTEXT

PopularizaConofthetechniquesusedbythe

police

CriminalsaremoreaLenCveandcauCous!

Humanodor

GCxGC-ISCCRivadelgarda2018

Page 3: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

USEOFTRAINEDDOGS

•  SufficientforidenCficaConofaperson•  LimitedprobaCvevalueincourtsofjusCce

•  NeedforcorroboraCveevidencebyanalyCcaltools:•  SupporttheinformaSonprovidedbydogs•  ProbaSvevaluetoevidenceincourtsofjusCce

GCxGC-ISCCRivadelgarda2018

Page 4: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

OBJECTIVES•  DevelopaglobalstrategytocharacterizetheolfactoryfingerprintsofindividualsusinganalyScalandstaSsScaltools•  VolaClecompoundsattracelevels:preconcentraConsteprequired•  Complexmixtures:mulCdimensionalseparaCon(GC×GC-MS)

•  QuesContobeanswered•  Isthecomparisonofan“odor”referencechromatogramtoachromatogramobtainedusinganodorsamplefromasuspect(crimescene…)sufficienttoprovethattheodorbelongstothesameperson?

GCxGC-ISCCRivadelgarda2018

Page 5: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

GLOBALSTRATEGY

SAMPLING/PANEL SEPARATIONANDDETECTION DATAPROCESSING

GCxGC-ISCCRivadelgarda2018

Page 6: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

PRECONCENTRATIONANDANALYSIS:PURGEANDTRAP-GCXGC

ThermodesorpSoncoupledwith

GC×GC-MS

VSP4000,AcConEurope(Sausheim,France)

Sampletemperature=190°CPurgeflow=20mL/minPurgeSme=20minSplit=0mL/min

DesorpConopCmizaConDOE:•  syntheScmixtureofhuman

odor(80compounds1)•  fullfactorialdesign24

1-Cuzueletal.,Areview:Origin,analyScalcharacterizaSonanduseofhumanhandsodorinforensics,2017,JournalofForensicSciences

Directsampling

Indirectsampling

DB1MS-DB17012°C/min–modulaSon8s

GCxGC-ISCCRivadelgarda2018

Page 7: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

CHROMATOGRAMOFAREALSAMPLE8s

0 86min

2nddimen

sion:DB1

7-01(m

id-polar)

1stdimension:DB1-MS(apolar)

•  ShimadzuGC×GC/MSQ2010Plus•  Gradient:2.5°C/min40°Cà250°C

NonanalDecanal

5-hepten-2-one,6methyl

α-pinene

5,9-undecadien-2-one,6,10-dimethyl(E)1,7-octanediol,3,7-dimethyl

Ethanol,2-phenoxy

Phenol,p-tert-butyl

TerSaryodor

Primaryandsecondaryodor

GCxGC-ISCCRivadelgarda2018

Page 8: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

COMPARISONOFREALSAMPLES?

•  Complexsamples

•  Comparisonisnottrivial

•  Alotofdatatoprocess

•  NeedforanautomateddataprocessingtoextractrelevantinformaSon•  Needforapanelofpersonstoevaluatethestrategy

GCxGC-ISCCRivadelgarda2018

Page 9: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

Panelof119persons

•  Phototype1-skinissunsensiCveanddoesnotburn•  Phototype2-intermediateskin•  Phototype3–welltanningskin•  4directsamplingsofhands/person(Sorb-star®)

•  15minutes•  Blank(samplingroom)

•  TD*-GC×GC-MS**•  3chromatograms/person*Cuzueletal.,SamplingmethoddevelopmentandopSmizaSoninviewofhumanhandodoranalysisbythermaldesorpSoncoupledwithgaschromatographyandmassspectrometry,2017,Anal.Bioanal.Chem.

**Cuzueletal.,Humanodorandforensics.OpSmizaSonofacomprehensivegaschromatographymethodbasedonorthogonality:hownottochoosebetweencriteria.,2017,JournalofChromatographyA

gender age(years) phototype

total ♂ ♀ 10-23 24-36 37-81 1 2 3

119 61 58 39 39 41 25 79 15

CHROMATOGRAMSOFREALSAMPLES:PANEL

GCxGC-ISCCRivadelgarda2018

Page 10: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

DATAPROCESSING/BAYESIANAPPROACH

GCxGC-ISCCRivadelgarda2018

Page 11: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

•  FrequenCstApproach

•  BayesianApproach

ü

ü

ü

ü

CHROMATOGRAPHICDATAPROCESSINGWITHMATLAB

Conversionoffiles Pre-treatment DetecSonofpeaks

Transferofdatainthelibrairies

TreatmentusingstaSsScs

•  DetecConoflocalmaxima

•  ExtracConofassociatedinformaCons

•  BaselinecorrecCon

•  SelecConofinvesCgatedzones

ExportincompaCbleformat

(mzXML)

ImportofdatatoMatlab

•  DetecConoflocalmaxima

•  ExtracConofassociatedinformaCons

(alkanes,1t,2t,LRI,MSspectrum,name)

•  ImporttoNISTandownlibrary(3persons)

(>600compounds)

•  Libraryupdate(knownodorcompounds*)

•  IdenCficaConandpeakassignaCon

*Cuzueletal.,Origin,analyScalcharacterizaSonanduseofhumanodorinforensics,2017,J.ForensicSci.

1chromatogram 1vectorcorrespondingto600compoundspeakintensityGCxGC-ISCCRivadelgarda2018

Page 12: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

H0:thetwochromatogramsareobtainedfromthesamepersonH1:thetwochromatogramsareNOTobtainedfromthesamepersonIfDrepresenttheobserveddata(thetwochromatograms),Bayesformulagives:

Protocole:

•DefiniConofadistancedbetween2chromatograms(D≡d)

•Panelofchromatogramsofindividuals(119personssampled4Cmes)spliLedinindependentcalibraSonandtestgroups

•CalibraCongroupèesCmaConofdistribuSonsofdforcouplesofchromatogramsfromthesamepersonf(d|H0)andfromdifferentpersonsf(d|H1)

•TestgroupèesCmaConofperformance(AUC,sensiCvity,spécificity)

P(H0 |D) =f(D |H0)P(H0)

f(D |H0)P(H0)+ f(D |H1)P(H1)

BAYESIANAPPROACH(APOSTERIORI)

GCxGC-ISCCRivadelgarda2018

Page 13: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

EsSmaSonofthestaSsScallikelihoodOpSons:d:distancesbetween600-vectorsofintensiCes:

a)euclidiandistanceb)1– PearsoncorrelaSoncoefficientc)1– SpearmancorrelaSoncoefficient

•intensiCesnormalized/binarized(b=c)CalibraCongroup(260chromatograms/75persons)-341couplesofchromatogramsforH0(sameperson)-33329couplesdechromatogramsforH1(différentpersons)èhistogramsofdvaluesforH0andH1Ajustmentofhistogramsusingseveralgaussiancurvesè f(d|H0)andf(d|H1)

BAYESIANAPPROACH:CHOICEOFDISTANCEBETWEENCHROM

GCxGC-ISCCRivadelgarda2018

Page 14: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

•ProbabiliCesapriori:P(H0)=P(H1)=0.5•FicCCousexamplesofstaCsCcallikelihood

P(H0 | d) =f(d |H0)P(H0)

f(d |H0)P(H0)+ f(d |H1)P(H1)

BAYESIANAPPROACH:EXPECTEDRESULTS

Distancebetweenchromatograms Distancebetweenchromatograms

GCxGC-ISCCRivadelgarda2018

Page 15: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

BAYESIANAPPROACH:RESULTSUSING600COMPOUNDS

distanceintensiSes euclidian 1–ρPearson 1–ρSpearman

normalized 62.7%/64.6% 74.6%/74.7% 92.4%/93.6%

binarized 88.4%/91.6% 89.6%/91.7%

N.B.usingthetestgroup,thereare173/9418couplesforH0/H1respecCvely

2modes!

GCxGC-ISCCRivadelgarda2018

(%AUCcalibraCon/%AUCtest)

Page 16: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

•DiscriminaCngcompoundsforH0andH1:thosewhich intensitydifferences|∆i|aresignificantlylowerforH0thanH1• QuanCficaCon :p-value usingunilateral Fisher test (binarized intensiCes) orWilcoxon(normalizedintensiCes)on|∆i|•Examples:

BAYESIANAPPROACH:DISCRIMINATINGCOMPOUNDS

GCxGC-ISCCRivadelgarda2018

Page 17: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

Binarized

Normalized

BAYESIANAPPROACH:RESULTSUSINGDISCRIMINATINGCOMPOUNDS

GCxGC-ISCCRivadelgarda2018

(%AUCcalibraCon/%AUCtest)

Page 18: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

BAYESIANAPPROACH:RESULTSUSINGDISCRIMINATINGCOMPOUNDS

•Thresholdπ value–log10(p)ofFishertest(binarizedintensiCes)orWilcoxon(normalized intensiCes) :opCmizedvalueobtainedusingcrossvalidaSon (K=3)oncalibraSongroup

distanceintensiSes euclidian 1–ρPearson 1–ρSpearman

normalizedπ =12/61comp.

76.2%/73.9%

π =13/54comp.

78.1%/75.2%

π =7/146comp.

97.5%/98.2%

binarizedπ =18/82comp.

93.1%/94.8%

π =18/82comp.97.4%/98.1%

(%AUCcalibraCon/%AUCtest)

GCxGC-ISCCRivadelgarda2018

Page 19: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

Discussion

Performances• Adequate distanceèquanStaSve exploitaCon of compounds intensiCes despite theanalyCcalvariability•SelecSonèsecondmodesoff(d|H0)etf(d|H1)arestronglydecreasedèbeLerresults•Binarized:moreparsimonious(82/146compoundstobeused)•67commoncompoundsforbothclassifiersNotabene•samedirectsamples•nopolluConbyotherodors

intensiSes AUC sensiSvity specificity nb.compounds

binarized 97.4%/98.1% 89.4%/90.0% 94.9%/92.5% 82

normalized 97.5%/98.2% 89.1%/85.9% 93.7%/95.0% 146

(%AUCcalibraCon/%AUCtest)

GCxGC-ISCCRivadelgarda2018

Page 20: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

CONCLUSIONANDPERSPECTIVES

ü Direct/nondirectsamplingproceduresforhuman(hand)odoranalysesü ComprehensiveGC×GC-MSmethodanddata(ToF)ü ValidaConofproceduresinthefieldwithdoghandlersü LargePanelofindividualstotestthemodelü Storageofsamples:standardizedprocedureü DataprocessinginprogressforrealapplicaCon

ü Differentsamples(directornot…)andsamplingcondiSonsü StudyofdiscriminaCngcompoundsü NormalizaConondiscriminaCngcompounds,morecomplexdistance…

ü ThefinalanswertothequesSonmustbeYESorNOnot98.2%GCxGC-ISCCRivadelgarda2018

Page 21: GC×GC-MS AND BAYESIAN TESTING IN FORENSICS … · GC×GC-MS AND BAYESIAN TESTING IN FORENSICS ... development and opmizaon in view of human hand odor analysis by thermal desorpon

ACKNOWLEDGEMENTS

THANKYOUFORYOURATTENTION!Dino

GCxGC-ISCCRivadelgarda2018


CS10 GC CS11 GC CS12 GC

Part Number INdex ..... GC & GC/MS, 294 121-2323LTM ..... GC & GC/MS, 294 121-3822 ..... GC & GC/MS, 256 121-3822E..... GC & GC/MS, 256

Stadtteil Bad Neuenahr Dienstleistung | Handwerk Einkaufen … · 2019. 7. 15. · Stand: April 2019 GC GC GC GC GC GC GC GC GC GC GC GC GC GC GC 41. Seidenblumenhaus Elfleur Telegrafenstraße

Digital Forensics or Cyber Forensics My Contribution

COMPUTER FORENSICS · 2019-08-24 · 1.0 Computer Forensics In Today’s World 1.0 Intro To Computer Forensics 2.0 Need For Computer Forensics 3.0 What is Cyber Crime 4.0 Forensics

MANTELERÍA GC / NAPPAGE GC NAPPAGE GC CONJUNTOS …

Comp ter Forensics It’s NotComputer Forensics: It’s … ter Forensics It’s NotComputer Forensics: ... Computer Forensics Can be Useful with ... Solid state drives & deleted file

Computer forensics - Jordan University of Science and ...tawalbeh/aabfs/presentations/computer_forensics.pdf · 29.08.2006 Computer forensics 2 Computer forensics Definitions: Forensics

OleDetection Forensics and Anti-forensics of Steganography ...users.cs.fiu.edu/~fortega/df/research/infohiding/Erbacher-Ole... · OleDetection—Forensics and Anti-Forensics of Steganography

MODEL: GC-269S GC-309B GC-269SA GC-309BA GC-269SV GC …

Cloud Storage Forensics - SANS Computer Forensics

COE589: Digital Forensics - ccse.kfupm.edu.saahmadsm/coe589-122/00_Overview_Logisti… · Digital Forensics computer forensics mobile forensics network forensics ... COE589 - Ahmad

Forensics · Disk Forensics Mobile Forensics E-mail investigations Questioned document Cryptography, examination Steganography Live Forensics and Network Forensics Audio/video authentication

COMPUTER FORENSICS - Boise Chapter€¦ · 3 Mobile device forensics 4 Other 5 References Computer forensics Main article: computer forensics ... 1.19 Computer Forensics Solution

· PDF fileCriminal investigation/ Forensics Example. ... GC-MS 6800, LC-MS 1000, and ... Skyray has been the only authorized distributor of NIST database

Generalized Correspondence-LDA Models (GC-LDA) for ... · The GC-LDA and Correspondence-LDA models are extensions of Latent Dirichlet Allocation (LDA) [3]. Several Bayesian methods

Acquisizione Laboratorio Disk forensics Network forensics

iPhone Forensics Methodology and Tools · Forensics methodologies, iPhone forensics, forensics tools, digital forensics evidence handling, INTRODUCTION iPhone mobile phone is becoming

Implementation of Forensic Analysis Procedures for ...Android Forensics, Instant Messenger Forensics, Viber Forensics, WhatsApp Forensics. 1. INTRODUCTION ... communication medium

Anti-Forensics and Anti-Anti-Forensics

MemTri: A Memory Forensics Triage Tool Using Bayesian … · 2017. 11. 12. · tal forensics is “a process in which digital evidence is ranked in terms of importance or priority”

DefCon 2012 - Anti-Forensics and Anti-Anti-Forensics

History of Forensics CHS. Define Forensics Forensics is the application of science to law

Live Forensics Investigations Computer Forensics 2013

Is Mobile Device Forensics Really Forensics?

© The Forensics Files Lincoln-Douglas Debate The Forensics Files The Forensics Files

MemTri: A Memory Forensics Triage Tool Using Bayesian ......MemTri: A Memory Forensics Triage Tool Using Bayesian Network and Volatility Antonis Michalas Cyber Security Group Department

USB FORENSICS -PRODISCOVER USB FORENSICS –ENCASE V7csc.csudh.edu/cae/.../2013/11/All-is-not-Lost-Forensics-on-a-USB-Ale… · USB FORENSICS -PRODISCOVER USB FORENSICS -PRODISCOVER

Computer Forensics using Bayesian Network: A Case Study · Computer Forensics using Bayesian Network: A Case Study Michael Y.K. Kwan, K.P. Chow, Frank Y.W. Law, Pierre K.Y. Lai {ykkwan,chow,ywlaw,kylai}@cs.hku.hk

The Econometrics of Bayesian Graphical Models: A Review With … › 92634 › 1 › MPRA_paper_92634.pdf · 2019-09-26 · The econometrics of Bayesian graphical models 5 GC is complete

SULTANATE OF OMAN · 2015. 10. 18. · Oman Elec GC.1 GC.2 GC.3 GC.4 GC.5 GC.6 GC.7 GC.8 GC.9 GC.10 GC.11 GC.12 GC.13 GC.14 GC.15 tricity Transmis Introductio Objective Scope of Grid

Computer Forensics - Dipartimento Di Informaticaads/ads/Sicurezza_files/Presenta... · 2017-05-09 · Computer Forensics 3 Dalla digital forensics alla computer forensics Digital

PEGASUS GC-HRT€¦ · Our global network of sales/ support is dedicated to customer service and satisfaction, ... environmental, forensics, or life science (metabolomics) industries,

Network Forensics PPrinciples of Network Forensics

Forensics & Anti- Forensics - Power Of Communitypowerofcommunity.net/poc2007/casper.pdf · Anti-Forensics • Wipe can reply all Host Forensics Tools • Counterfeit Evidence •