Crime scene- footwear marks and impressions PDF

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footwear marks and impressions, what can be obtained from footwear marks, Maximising the recovery of footwear marks at a crime scene, how footwear marks are formed, positive and negative footwear marks, wet and dry origin footwear marks, two dimensional image, three dimensional image, chemical enhan...

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Lecture 4

Footwear -

Footwear marks are influenced by both the weight of the person and the surface over which the person has travelled The impression can be made by either the undersole of the shoe worn by the suspect (footwear) or by the suspects barefoot (footprint) Each manufacture creates a unique and distinctive under soles as well as different uppers Some under soles are cut from large pieces of pre-moulded rubber this can result in individual features injection- moulded under soles should have an identical under sole pattern As the shoes wear the pattern on the under sole will change Depth is reduced or may disappear altogether People walk in different ways, placing their weight on different parts of the under soles this creates a unique pattern of wear Contact between the ground and under sole causes unique areas of damage

The following information may be obtained from footwear marks: - Identification of footwear - Elimination of footwear - Participation of suspect in a crime - Location of mark - Rebuttal or confirmation of alibis - Determination of shoe brand - Linking of suspects to the Crime Scene - Determination of Shoe Size - Number of perpetrators - Association with other evidence - Gait characteristics - Tracking Maximising the recovery of footwear marks at a crime scene - Important to gain as much information as possible before entering the crime scene: Where? When? What? Why? Who? How? - Can show: external areas of the crime scene, point of entry to the crime scene, the path through the crime scene, point of occurrence of the crime, near other footwear marks and point of exit. How footwear marks are formed Transfer of a contaminant - When the outer sole of an item of footwear comes into contact with a surface, it is very likely that that trace material/contaminant will be deposited and/or removed from the surface to produce either a visible or latent footwear mark - High chance of retrieving the mark - Contaminants can be either a liquid or a solid - Contaminants transferred to a surface of similar material will unlikely have a visible

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footwear mark Contaminants transferred onto a contrasting surface will have a better chance to form a visible footwear mark

Positive and negative footwear marks Negative footwear mark - Outer sole of footwear removes a contaminant from a surface which leaves a footwear mark that represents some or the entire outer sole pattern Positive footwear mark - Outer sole of footwear deposits a contaminant onto a surface which leaves a footwear mark that represents some of the entire outer sole patterns Wet and dry origin footwear marks Wet origin footwear marks - Footwear or surface is damp or wet - More likely to adhere to a surface Dry origin footwear marks - Both the footwear and surface is dry Two-dimensional image - Can be defined as having or appearing to have length and width but no depth - Can be found on a tiled floor, piece of paper, carpet or wood flooring. Surfaces can be classed as porous or non-porous - The image can be either latent or visible. - If the image is visible, it can be photographed using the right-angled scale - Where the image is not visible to the human eye, a high-intensity light source positioned close to the surface of interest is used, casting oblique lighting across the surface thus producing a low angle of the incident light. The shadows from the deposits adhering to the surface will provide the vital contrast. Within the right lighting conditions, this can then first be photographed using a right-angled scale. - To enhance a latent footwear mar fingerprint powders can be used - Powders are selected by identifying the surface that the footwear mar is located and possible contaminants on that surface - Smooth surface- non-porous surfaces e.g. glass, glazed ceramic tiles or similar items - Rough surface- porous surface e.g. any surface which is not smooth - Aluminium powder/brass flake powder - considered sensitive - U.P.V.C even though is smooth best results are obtained using black magnetic powders - black/white non-magnetic granular powder is less sensitive than flake powders. These are used on smooth clean surfaces when there is a problem with contrast using aluminium powder - Magnetic flake and magnetic granular powder, rough surfaces - Gel lifters - Fablon sheets - Electrostatic detection apparatus (ESDA) - Electrostatic lifting apparatus (ESLA)

Three-dimensional image - Has or appears to have length, width and depth - Found on a surface where she shoe sank, leaving an impressed image e.g. soft soil - This records the length, width and depth data - 3D images recovered indented in the soil must first be photographed using the rightangled scale. The image can then be recovered by casting the mark using a dental stone mixture that is poured over the indentation and allowed to dry; it is then carefully removed. This method can reproduce fine details of the undersole - Snow wax or hairspray Chemical enhancement - Bluestar - Luminol - Fluorescein - Ninhydrin - Acid black Cinderella analysis - Does the shoe fit? - Has these shoes been worn by that person? - No two persons have identical feet - Length and width and shape of foot - Characteristics on side of the foot - Tension points on top of foot - Tension points under the foot - Pressure points of the toe tips Legislation - New legislation introduced on 1st january 2006 allowed the covert taing of footwear impressions of detainees when arrested or a recordable offence, with or without their consent Serious and organised crime and police bill -”section 61a of police and criminal evidence act 1984 was inserted by section 118 of the serious Organised Crime and Police Act 2005 and amended by the serious organised crime and police act 2005.” Methods of taking footwear - Printscan - Scanner - WD40 Her majesty's inspectorate of constabulary’s (HMIC) produced two thematic inspection reports - Under the microscope in 2000 - Under the microscope refocused” in 2003. - Under the microscope stated: - “Forces, where there is no footwear system in place, should review their approach to this valuable source of evidence and intelligence.”

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Reinforced by Home Office Findings 236, research development and statistics directorate (2004) contributions of shoe mark data to police intelligence, crime detection and prosecution,” Home Office Findings 236 also highlighted that around 80% of the thirty-one Police Forces surveyed organised their footwear marks on computerised systems. However a number of Forces organised their footwear marks on a divisional basis and this information was only shared with other divisions on request rather than a network computer system. The report also found that very few police focus routinely did mark to mark searches and in some cases there was no system in place to do any kind of searches

The police standards unit conducted research into the retrieval of footwear at burglary crime scenes over the period 2005/2006 the difference between forces found to be: - Best achieving 35% - Worst achieving 6% - DNA techniques bcame more advanced - The implemtnation of the DNA expansion programme - The level of DNA retrieval has increased - Retrieval of footwear marks has reduced The footwear technician operates within the forensic intelligence department - Identify footwear from scene marks loaded - Code the marks and search against other loaded scene marks - Compare scene marks against custody impressions loaded onto the database - Identify crime series by linking scenes from the different divisions, and attempting to link suspects and crime scenes together - All crime scene impressions loaded are checked daily; it is the footwear officers task to compare like for like crime scene marks to establish a possible crime scene to crime scene link. All footwear that is scanned in the custody suite is checked for any possible links Storage of images - SICAR; this acronym stands for shoeprint image capture and retrieval. The solemate reference collection is a database within SICAR - The forensic science service reference collection - FFS footwear intelligence technology system (fit) - Treadmark - Napier, an independent company based in york - Senlac forensic services - Lancashire and west yorkshire police - August 2005 - National shoe mark workshop - Acpo and psu - Lancashire police - National intelligence model - Level 1, level 2, level 3 - All systems had different coding systems

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2008 Npia forensic s 21 National footwear reference collection Launched april 2009 Npia and bluestar software “Nationally agreed language” Complete by december 2009

Case study - Peter voisey aka smith, born july 5th 1971 - Difficult upbringing - Petty crime as a child - Helsey hall nr doncaster aged 9-15 - Guilty of indecently assaulting a 12 year old girl in macclesfield in 2001 - December 2005 - 6 year old girl abducted from the bath in her house - Found naked in an alleyway, sexually abused - DNA and footwear mark...