PATTERN RECOGNITION OF WEAR, CLASS AND IDENTIFYING .

PATTERNPATTERN RECOGNITIONRECOGNITION OFOFWEAR,WEAR, CLASSCLASS ANDAND CS ININ FOOTWEARFOOTWEARIMPRESSIONIMPRESSION EVIDENCEEVIDENCEcaes MediDepartment of Medical IllustrationUniversity of Limpopo, Medunsa Campusovicl IllustratiAudiisual Ser-VHoosain M Ebrahim&on

IMPRESSION EVIDENCEObjects or materials which haveretained the characteristics of otherobjects or materials which havebeen impressed against them

Footwear impressions can bepositively identified as havingbeen made by a specific shoe

PHOTOGRAPHY OFFOOTWEAR IMPRESSIONS General crime-scene photographs Examination quality photographs

OBLIQUE LIGHT PHOTOGRAPH OFTHREE-DIMENSIONAL IMPRESSIONSCamerao-45o-30o-15Light source(Impression)

OBLIQUE LIGHT PHOTOGRAPH OFTWO-DIMENSIONAL IMPRESSIONCameraLight is reflected off dust particlesand into cameraLight source(Impression)

LIGHTINGLight source3rd position0oo290o70o90o270190Light source2nd positionLight source1st positiono180o

WEAR OF THE SHOE Position of wear Degree of wear

Wear - The erosion of the outsoledue to frictional and abrasiveforces that occur between theoutsole and the ground

INFLUENCES ON THEWEAR OF SHOE OUTSOLES Foot type andfunction Occupation Habits Body typeShoe styleShoe materialsWalking surfaces

Wear patternRefers to the wear on the entireshoe or a portion of the shoe

Wear patternAnatomical wear pattern

Wear characteristics alone arenot accepted as a means ofpositive identification

CLASS AND IDENTIFYINGCHARACTERISTICS Knowledge Pattern recognition Assessment

CLASS CHARACTERISTICS Size Pattern design Contour of imprint Shape

COMBINED CLASSCHARACTERISTICS Size Design

IDENTIFYINGCHARACTERISTICSResult when something is randomlyadded to or taken away from a shoeoutsole that either causes or contributesto making that shoe outsole unique

Pattern Recognition Techniquesused as searching criteria

RECOGNITION OFMANUFACTURINGMETHODS

HAND ENGRAVED MOULD-MAKINGTwo hand-engraved moulds using same templatesand pantograph but resulting in different “gross designs”PantographTemplates

TypesPreliminary classificationFeature classification

Shoe impressionsPartialComplete

Shoe sole collection systemsassist in determining theclassification of full shoeimpressions

Different pattern designs andpossible small differenceswithin patterns

RecordedImpressions(filed)Pattern designsFeatures

FOOTWEAR IMPRESSIONSA valuable form of physical evidenceProvide an important link betweenthe criminal and the crime scene

Development offootwear collectionKnown criminalsShoe Stores

ESTABLISHMENTOF A DATABASE Link crime scenes Possible suspect Brand name of shoe

FEATURE CLASSIFICATION Pattern on edgeToe areaHeel areaCirclesShapes within shapesPatterns surrounding motifs,letters, numbers

TongueVampHeel collarLogoHeel back strapHeel quarterHeel stabilizerMulti-density midsoleOutsoleMedial sideA r chLateral sidea r eaBrand Nameor Logo AreaBorder

PATTERN DESIGNS A hollow circular area insidea circular shape Numerals inside a circular shape Unusual shaped studs on the edgeof the sole Motif engraved in the border of the sole ETC

FEATURE CLASSIFICATIONCATEGORIESThe edge areaCircular areas surrounded by a valleyCertain featuresPatterns on soleA pattern/shape inside anotherpattern/shape The toe/back of heel area

MAIN GROUPS OFTHE PATTERNSDigit catedCrepe and plainContinuous border

PATTERN TYPES INTHE MAIN GROUPSDigit (second)Shape01CircularTriangular Width of line/broken/continuoushigh/low width of line/broken/continuousBar patternContinuous border continuous border of the shoe soleWave or Zig-Zag

First Digit Second Digit71PatternShapeContinuous TriangularBorderThus 71 means that there are triangular studsin a continuous border

DEFINITIONPattern recognition is the identificationof normal structure and appearance onan image and those variations ofappearances which may indicate adisordered state

PHYSICAL PATTERNSIN IDENTIFICATIONIdentification based on structuralfeatures is the recognitionof a physical pattern

PHYSICAL PATTERNSIN IDENTIFICATION Physical matching Comparison of markings General shape or form comparison

Database of: Shoeprints at scene of crime Shoes of suspects Shoes on the market

NEURAL NETWORKSIN FORENSIC SCIENCE

University of Limpopo, Medunsa Campus PATTERN RECOGNITION OF WEAR, CLASS AND IDENTIFYING CHARACTERISTICS IN FOOTWEAR IMPRESSION EVIDENCE PATTERN RECOGNITION OF WEAR, CLASS AND IDENTIFYING CHARACTERISTICS IN FOOTWEAR IMPRESSION EVIDENCE M e d i c a l I l l u s t r a t i o n & A u d i o-V i a l S e r v i c e s. IMPRESSION EVIDENCE Objects or materials which have retained the characteristics of .