September 20, 2012 - AFFIDAVITS & EXPERT REPORTS

AFFIDAVITS & EXPERT REPORTS

DPS CONTAMINATION REPORT SEPTEMBER 20, 2012

t5L-41623ContaminationReport On August28,z0tz while reviewingthe Genemapper lD-Xinjestionlist dated g-14-IzforcaseL5L4t623, I noticeda mixtureprofilefor sampleCO91.36.2, a mini-tapecollectionfrom one sideof a dish towel.Analysis of the sampleshowedthat LanBundy,a TraceEvidence analystwithinthe Lubbock lab, could not be excludedasa contributorto the profile.I notifiedcathy Mccord,DNAtechnicalleader, on thisdate.On August29,2072,duringthe secondreadof the 3130x1 run by SarahRothwell, it wasnoted that BrentHester,anotheranalystwithinthe DNAsectionof the Lubbocklab,couldnot be excluded asa contributorto sampleCO341.40.1, a bloodstaincollected on gauze.SarahnotifiedCathyMcCordabout the presence of thiscontamination immediately afternotingit.

Thesampleswere re-setup for 3130x1 injections on August30, ZOLZ andSeptember 3, ZO1Z. The contamination wasstill presentin bothre-injections.

Thesamples were both re-amplified on September 3,?OLZ,and the contamination wasstillpresentin thesesarnples.

ForsampleCO341.40.L, a second portionof the stainwascollected, howevertherewasno sampleremaining for CO91.36.2-This second portionfrom the stainon the gauzewasextremety faint,irnplying that the originalstainwasalsolikely verysmallandweakotherwisemorestainwouldhavebeenretained.

Thisportion,co34 1.40.1 {2),was extractedandamplified.Thequantitation valuefor thissamplewas0.00448ng/uL, compared to .O4tLng/uL for the originalportion,andonlyone allelewaspresentin the DNAprofile.In addition, a Hematracetest wasdone on a portionof this sample.Theresultswere negative,however it is not possible to determineif this is because the sampleis not of humanoriginor because the samplewastoo weakto test accurately.

I believethat the contamination of sampleCOg1.35.2

by Mr. Bundyoccurredduringthe sample collectionprocess.

Thissamplewasa "mini-tape"collection of evidence from a dishtowel.This techniquehasbeenshownin the pastto be hightysensitive.

Duringthe collection process on Augustg, 2012,Mr. Bundywas in the room discussing the collectionprocessfor the hair evidencein thissarne case'Mr, Bundywas approxirnately fiveto sixfeet awayfrom the evidenceandstandingbehindme while I collectedthe rnini-tapes, howeverhe wasnot wearinga surgical rnask.lt is possible that while talkingto me, Mr. Bundy'sDNAwastransferred to the evidence.

Anotherpossibility is that Mr. Bundy was presentduringthe initialscreening of thisevidence on Julyt3, ZAIZandthat hisDNAcouldhave beentransferredto the evidenceat that time. However,Mr. Bundystatedthat he does not recall interacting with this pieceof evidence on that day.

It is more difficultto ascertain whenthe contamination of sampleco34 l.4o.l.occurred.

Therewere severalpiecesof gauzesubmittedin thiscase.I recallthat duringthe collection of the stains,one piece of gauzefell off the scissors asI wastransferringit from the zip lockit was storedin into a newziplock for frozenstorage.

Thispiecefell onto a pieceof butcherpapercoveringrnyworkarea,and I pickedit up off the butcherpaperto placeit into the ziplock.I waswearinggloves,mask,gownand capwhile collecting thisevidence.I am not certainthat the pieceof gauzethat fell is the samesample that showedcontamination, but thisis the onlyincidentI canthinkof that couldhaveleadto the contaminationlt is possiblethat my gloveshad pickedup a shedskinflakeor that onehadfallen on to the butcherpaperand waspickedup by the gauze.

The uniquecircumstances of thiscasecouldhaveplayeda role in why contarnination waspresent.The amountof viableDNAwasverysmall.tt is my understanding that afterthe casewasadjudicated, the evidencewasstoredin a non-temperature controlledstorageroom. Manyof the bagsthat the evidence was storedin showeddamagefrom rodentsor insects,indicatingthat the evidencewasexposedto the outsideenvironment.

In addition,someevidence wasmisplaced or lostentirely,andthe DNAprofile from one of the law enforcementofficersthat handledthe evidencecannotbe excludedfrom threeof the samples.

Out of 99 samples that had DNAanalysis doneandthat werestoredoutsideof DpScontrol, yieldeda full profile,with halfof thesecomingfrom the sarneitem.In addition,the only6 samples evidencewascollectedalmost19yearsago.Whifefull profilescanbe generated from DNAthisageor older,theseare generally from iternsthat havebeenstoredunderproperconditions.

The agecornbinedwith the lackof properlongtenn storagelikelyled to the presence of degradedDNA on the samples, whichthe numerouspartialevidentiary DNAprofilesindicates aswell.Thepresence of suchminimalDNAin a mostlydegraded stateallowsfor a muchhigherprobability of contaminating profiles.With so muchdegradedevidentiaryDNApresent,the presenceof minisculeamountsof nondegradedcontarninating DNAis preferentially amplifiedoverthe degradedDNA,andthusoverpowers the signalfrom the degradedDNA.Furtherevidence of thisis the observation that bothof the profilesaremorecompleteprofilesthan rnostof the evidentiary contaminating samples in thiscase. ln the future,greatercarewill be takenwhencollecting samples.

Specifically, I will be moreawareof the presenceof other analysts in the areawhencollecting traceDNAsamples, and requirethat anyanalysts wear masksif talkingto me, no matterwherethey might be locatedin relationto the evidence.I will alsotake precautions to minimizehandlingthe evidence directly,evenwhilewearinggloves.

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