Monday, June 3, 2019

Development of Forensic Science Methods

Development of Forensic scientific discipline MethodsThe Criminal Justice System of England in the 18th century initially consisted of perpetrators being privately prosecuted by their victim, with the victims playing the role of the criminal investigator gathering and submitting march, paying fees to cover the expenses of the constables time in order to apprehend the suspect, filing charges with the local magistrates and presenting evidence to the princely jury. However, the development of the CJS has resulted in professional bodies gathering and submitting evidence, alongside the representation of victims in court by the Crown Prosecution Service (CPS), victim support run and there argon an array of specialist courts in existence who handle cases specific to their knowledgeable subject.The Contribution of Forensic Science to Police InvestigationAs cited by Pyreck (2007, p. 4), The National Institue of Justice (NIJ. 1998) defines forensic science as the application of scientific knowledge to the legal system. Thornton (1997) observes, Forensic comes to us from the Latin forensus meaning of the forum. In ancient Rome, the forum was where governmental debates were held, but it was also where trials were held. It was the courthouse. So, forensic science has come to mean the application of the natural and physical sciences to the resolution of conflicts within a legal roachting. The Home Office Report (2005, p. vii) proposes that factors such as the degree of integration and communication between police and scientific support appeared to be consequential in determining retrieval rates. Forensic science was initially a conventional means to corroborate suspected offenders, however due to procedures such as DNA testing the report goes on to state that there is an increase in the proportion of volume evil offences detected using forensic evidence. In the UK, it is estimated that, for directly detected volume crimes, the main evidence securing the detection was forensic in more than one quarter of cases. Databases such as AFIS and NDNA run systems which bid comparable results from forensic evidence to apprehend offenders on the system with a detection rate of attaining perpetrators in seven in ten cases, which can engender to be the solution to a further 0.4 open cases on the system. Fingerprint evidence can be found 41% of the time at scenes of fomite crimes, 45% of non-residential burglaries and one in three residential burglary scenes with 10% of scenes providing DNA evidence. However, it proves to be difficult to collect forensic evidence when scenes are inaccessible, have been purged or the offender has been vigilant. It can also be difficult to convict suspects with a positive DNA match when there is insufficient evidence or the various(prenominal) provides a legitimate alibi. The use of forensic measures in court however, have proven to impact cases in a positive light namely for theft, run into and burgulary cases, with an inc rease of 17% for burglary alongside this, the appraisal of DNA and leafprint evidence augments a jurys decision to convict in cases of homicide and rape.Methodology Applied when Gathering breed Spatter Evidence and Other Samples in Criminal InvestigationForensic Scientists can gather a more accurate profile of the perpetrator and how the crime was committed by gathering and analysing the following specimensHair analysisFiber AnalysisGlass FragmentsPaint Chips AnalysisSoil AnalysisBallisticsToolmarksBitemarksFingerprints footwearTire ImpressionsBlood Spatter AnalysisDNA AnalysisBlood, Semen, and Saliva (DNA matching and typing blood-spatter analysisNonhuman DNA (dog, cat, deer, whales)Drugs (drug identification, forensic pathology)Explosives (bomb and arson identifications and beginning traces)Fibers (fiber typing, generator identification, and matching)Hair (hair typing and matching)Fingerprints (fingerprint matching, AFIS, etc.)Bones (gender and age typing, identification of remains weapon identification)Wound analysis (weapon typing physical movement patterning)Firearms and ammunition (ballistics and tool-mark identification) gunpowder residues (shootings, suicides)Glass (glass typing and matching)Foot, tire and fabric impressions (impression typing and matching)Paint (paint typing and matching in automobile collisions, hit and run)Petroleum products (product typing and matching)Plastic bags (typing and matching garbage bags as suffocation device or when used in transports)Soils and minerals (mineral typing and matching forensic geology)Tool marks (tool identification and matching homicides, burglary, post invasions, etc.)Wood and vegetative matter (plant typing and matching plant DNA)RAPD matching limnology, Forest Service LabInsects, larvae, maggots forensic entomology time of death fixture crumbles)(Kiely, F. T. 2006, p. 50)One of the underlying principles behind forensic analysis is the concept that when two individuals come in liaison with one another, or if an individual comes in contact with an object, there is a high probability of transfer of biological material (skin, hair, etc.). The transfer does not always have to be as obvious as blood, (Missouri offer Highway Patrol, p. 22). Due to this, it is important to collect samples from all those whom have been in contact with the victim and the scene of the crime to avoid wrongful implications by eliminating those individuals whom do not match the suspects DNA profile.Analysing Blood, Semen and Saliva SamplesHair is a biological specimen of the body and may be associated back to its source through DNA analysis (although DNA is not always successfully extracted from hair), (Missouri State Highway Patrol page. 30). Alternatively, materials stained with blood, seeded player, saliva can be collected, be ensured to be air dried before placed in a paper bag and sealed, then tagged with the identification of the contents, exhibit number, initial and date. For poriferous mate rial such as cloth and leather, investigators are advised to cut the area containing the stain however for nonporous materials such as glass and metal, stains are removed via a cotton swab that has been moistened with water and for liquid stains, a clean cotton swab is immersed in the sample. In terms of collecting semen samples, when the specimen is not drying-out, alternatively, condoms are to be frozen. When collecting a Buccal (Oral) swab, two to four swabs must be vigorously rubbed on the interior of the archness for a minimum of 30secs to a minute to recover epithelial (skin) tissue which must then be labelled with the individuals names.The Application of Fingerprint IdentificationWhen fingerprint evidence found in a body of water is collected, it should remain in the original water. A watertight container should be lowered into the water and allowed to fill. This allows the evidence to be placed in the container without exposing it to the air. If fingerprint evidence found i n water is allowed to dry before processing, the likelihood of developing prints of value dramatically decreases.(Missouri State Highway Patrol) page. 17)The Automated Fingerprint Identification System (AFIS) is a database which stores fingerprints that have been taken from suspects, whether they have been incarcerated or not due to which perpetrators are easily identified, without having a definitive suspect, as their prints are already present on the system. potential fingerprints on nonporous materials deteriorate rapidly upon prolonged exposure to high temperature and humidity. Consequently, items should be processed and/or forwarded to a laboratory as soon as possible A ruled scale should be used when photographing latent prints. Latent prints on materials are to be handled with gloves and placed in a cellophane protector, whereas latent prints on surfaces such as plastic cards, metal plates and glass bottles are dusted with finger print powder and then extracted with lifting tape and placed on a 3 x 5 card, which contrasts in color with the dusting powder used.Behavioural Science SupportAs cited by Alison and Rainbow (2011), the crime scene is presumed to reflect the murderers behaviour and personality in much the same way as furnishings reveal the homeowners disposition (Douglas et al., 1992 21)(Alison, L. and Rainbow, L. 2011 p. 19)Full verbal case briefing and access to the SIO/investigation teamAll relevant statementsCrime reportsAny officers reports/status reportsPathology and forensic reports/findingsFull set of crime scene and pst -mortem photographsAvailable analysis (e.g. telephony, palynology, entomology, etc)Relevant mapsVisit to all relevant scenes allows the BIA to gain fuller understanding of the decision-making process of the offender. Such information is not routinely available from (the above mentioned methods), where often the evidential focus is too restrictive to provide the necessary behavioural perspective.(Alison, L. and Rainbow , L. 2011 p. 25)Behavioural Investigative Advisors ( twist) provide a theoretical perspective in investigations via the use of forensic psychology to support investigators by implementing methods such as crime scene assessment DNA showing suspect prioritisation familial DNA nominal pool generation interview strategy media strategy offender background characteristics and investigation strategy, (Newburn, T. Et al. p.. 658).In order to fulfill an accurate evaluation, BIAs require case materials such asPlease refer to Appendix. 1 Example of the BIAs work.The BIA are able bodies whom provide expertness in offender profiling to connect cases where correlating physical evidence is not evident. The Serious Crime Analysis Section (SCAS) of the NPIA, through their mandate to collect and analyse a range of sexually motivated offences throughout the UK, now has more than 16,500 offences on ViCLAS (Violent Crimes Linkage Analysis System) database, (Alison, L. and Rainbow, L. 2011 p. 25).Appen dixAppendix 1 Example of the BIAs work.(Alison, L. and Rainbow, L. 2011) Case Study 2, folder 1FF, 194528.jpg

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