1 / 26

FORENSIC CRIME INVESTIGATION: THE ROLE OF DNA Prof Henri Fouche UNISA

FORENSIC CRIME INVESTIGATION: THE ROLE OF DNA Prof Henri Fouche UNISA. CAMPROSA CONFERENCE 08 – 11 NOVEMBER 2011 On board M.S.C. SINFONIA. INVESTIGATION.

tanika
Download Presentation

FORENSIC CRIME INVESTIGATION: THE ROLE OF DNA Prof Henri Fouche UNISA

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. FORENSIC CRIME INVESTIGATION: THE ROLE OF DNAProf Henri FoucheUNISA CAMPROSA CONFERENCE 08 – 11 NOVEMBER 2011 On board M.S.C. SINFONIA camprosa conference 8 - 11 November 2011

  2. INVESTIGATION • CRIMINAL INVESTIGATION is the quest for information that can be used as court evidence to secure the conviction of one or several suspects (LemanLanglois,2008:191) • FORENSIC INVESTIGATION is an investigation aimed at instituting court proceedings and where some or other scientific knowledge is applied to a legal problem (Lamprecht 2001:93) camprosa conference 8 - 11 November 2011

  3. PURPOSE OF AN INVESTIGATION • to establish whether an act may be labelled a crime • The collection of evidence to determine who is responsible and how they will be dealt with by the criminal justice system (Clark,2004:5-6) AN INVESTIGATION SHOULD BE ABLE TO ESTABLISH • The date, time and place where the crime occurred • The identity of the individuals involved in the planning, execution and after-effect of the misdemeanour • Whether there are witnesses present • If there is evidence of the criminal offence • The method of operation used to perpetrate the crime • If there is an indication of guilt or innocence to aid prosecuting authorities (Gilbert,2010:34) camprosa conference 8 - 11 November 2011

  4. COLLECTING EVIDENCE • all crime scenes, to a variable degree, contain physical evidence that may be visible to the naked eyes or so small that it can only be detected by a microscope • physical evidence comprises of all objects and material found in connection with an investigation that are instrumental in discovering the facts • the investigator should always be able to find evidence at the crime scene, linking the perpetrators to the crime scene and possibly connecting them to the elements of the crime (Gilbert,2010:80); (Saferstein,2004:5) camprosa conference 8 - 11 November 2011

  5. LOCARD’SPRINCIPLE OF EXCHANGE • Edmond locard, founder of the Institute of Criminalistics in Lyon, France, believed that suspects introduce items of evidence into the crime scene and remove items with them on leaving the scene • This exchange of trace elements involves items such as hairs, fibres, dirt, dust, blood, body fluids, skin cells and other materials Source: Criminal Investigation, 2010, 8th edition, James N.Gilbert.Upper Saddle River, New Jersey camprosa conference 8 - 11 November 2011

  6. FORENSIC INVESTIGATION • A detailed forensic investigation of the crime scene offers investigators the best chance of gleaning crucial information and evidence which may lead to the solving of a case • Investigators are advised to take advantage of the full range of specialist services available to them • The recovery of forensic material from a crime scene has the potential to provide evidence to identify the perpetrators and link the suspected perpetrator to the elements of the crime • Source IMO Resolution A.1025(26) Adopted on 2 December 2009 camprosa conference 8 - 11 November 2011

  7. CONCEPTS • DNA is the human genetic blueprint of an individual called deoxyribonucleic acid or DNA (Gilbert,2004:313) • GENETIC FINGERPRINTING is identifying specific patterns in the arrangement of DNA (Gilbert,2010) • DNA MOLECULE Two strands of randomly stacked intertwined chemicals forming a double helix resembling a twisted rope. The particular appearance of the bands provide the comparative image for positive identification (Gilbert,2010) • CRIMINALISTICS can be defined as the application of physical and biological sciences and technology to the scientific examination of physical evidence (Benett&Hess 2001:21) • INDIVIDUALISATION is a process that takes place through comparison, used to establish that a disputed sample when compared is from the same origin (Marais 1992:19) camprosa conference 8 - 11 November 2011

  8. DNA PROFILING • First used in genetic research & determining paternity cases in the 1970’s • 1985 Dr Alec Jeffreys,Univ.of Leicester, England published on identification of individuals on basis of DNA • 1987 First conviction obtained using DNA evidence (rapist sent to prison by England's Bristol Crown Court) • Most used in murder and rape cases Source: Criminal Investigation, 2010, 8th edition, James N.Gilbert.Upper Saddle River, New Jersey camprosa conference 8 - 11 November 2011

  9. CASE STUDY : WORLD TRADE CENTRE MASS MURDER, SEPTEMBER 11,2001 • 2,823 victims • 1.2 million tons of debris processed • 1,400 vehicles parked within scene processed • Destroyed buildings searched for evidence and human remains Source: Criminal Investigation, 2010, 8th edition, James N.Gilbert.Upper Saddle River, New Jersey camprosa conference 8 - 11 November 2011

  10. Sources and location of DNA • Eye glasses due to sweat or skin cells • Tape or ligature due to skin cells, saliva or hair • Dental floss, due to saliva, semen or skin cells • On a can due to saliva • On the rim of a glass due to saliva • The end of a cigarette butt due to saliva • On a washcloth, saliva, semen, hair, skin cells, blood • On blankets,sheets,pillows,semen,hair,skin cells, blood • On a hat,mask,bandanna,sweat, skin cells, hair, saliva • Clothing, hair, semen, blood, sweat (Gilbert,2004:316) camprosa conference 8 - 11 November 2011

  11. SAMPLES • Blood most commonly tested (liquid or dried stain) • Semen (sperm cell contains DNA) • Hair (root material contains cells necessary for analysis) • Successful extraction more dependant on size and condition of sample than age • Samples successfully obtained from 2,400 year old Egyptian mummy • Case study – Titanic victims buried in Canada camprosa conference 8 - 11 November 2011

  12. SAMPLES • DNA can be found in almost any cell of the human body • Can be obtained from items such as telephones, briefcases, car keys and gloves (low-copy DNA) New techniques allow criminalists to compare far fewer cells for a successful match • Small samples of low copy DNA pose greater risk of contamination as extraneous DNA more easily mixed into and confused with suspect DNA Source: Criminal Investigation, 2010, 8th edition, James N.Gilbert.Upper Saddle River, New Jersey camprosa conference 8 - 11 November 2011

  13. COLLECTIONBODY FLUID DETECTION DOG camprosa conference 8 - 11 November 2011

  14. INITIAL WALK THROUGH

  15. BRIDGE WING camprosa conference 8 - 11 November 2011

  16. THE INVESTIGATION

  17. SOURCE OF POSSIBLE EVIDENCE camprosa conference 8 - 11 November 2011

  18. EVIDENCE COLLECTION camprosa conference 8 - 11 November 2011

  19. SOURCE camprosa conference 8 - 11 November 2011

  20. SOURCE camprosa conference 8 - 11 November 2011

  21. SOURCE camprosa conference 8 - 11 November 2011

  22. FORENSIC EVIDENCE camprosa conference 8 - 11 November 2011

  23. DNA DATABASE: SOUTH AFRICA The South African Police Service Annual Report for 2010/2011 indicates that during the period of the report • 63 627 DNA samples were received for analysis • 100 026 DNA samples were analysed • 92% of DNA samples were analysed within 35 days Biology section- responsible for analysis of evidentiary material of biological origin,e.g. Body fluids, human tissue and hair with the aim of human identification through forensic DNA analysis and microscopial comparison camprosa conference 8 - 11 November 2011

  24. SOUTH AFRICAN POLICE SERVICE • The South African Police Service Annual Report for 2010/2011 indicates that evidence collection kits were introduced to facilitate the collection and laboratory processing of DNA samples and that these kits have assisted in protecting the integrity of exhibits and to ensure improved results in the laboratory. camprosa conference 8 - 11 November 2011

  25. MALMO DECLARATION INTERNATIONAL CONFERENCE ON PIRACY AT SEA 17 – 19 OCTOBER 2011, MALMO,SWEDEN The participants at the International Conference on piracy at Sea (ICOPAS) CALL ON companies and individuals to: • Facilitate prosecutions by assisting the International Police Organisation (INTERPOL) response teams, where possible, in preserving evidence at the scene of the crime camprosa conference 8 - 11 November 2011

  26. IN CONCLUSION • Most significant breakthrough in forensic science since the development of fingerprints • DNA can identify an individual to a certainty of one in a trillion • DNA has demonstrated the innocence of a significant number of accused suspects • Used to solve cold cases • Can be used to create data base similar to national fingerprint system Source: Criminal Investigation, 2010, 8th edition, James N.Gilbert.Upper Saddle River, New Jersey camprosa conference 8 - 11 November 2011

More Related