FORENSIC CRIME INVESTIGATION : THE ROLE OF DNA

FORENSIC CRIME INVESTIGATION: THE ROLE OF DNA

Prof Henri FoucheUNISA

CAMPROSA CONFERENCE08 11 NOVEMBER 2011On board M.S.C. SINFONIAcamprosa conference 8 - 11 November 2011INVESTIGATIONCRIMINAL 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 2011PURPOSE OF AN INVESTIGATIONto establish whether an act may be labelled a crimeThe 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 ESTABLISHThe date, time and place where the crime occurredThe identity of the individuals involved in the planning, execution and after-effect of the misdemeanourWhether there are witnesses presentIf there is evidence of the criminal offenceThe method of operation used to perpetrate the crimeIf there is an indication of guilt or innocence to aid prosecuting authorities (Gilbert,2010:34)

camprosa conference 8 - 11 November 2011A detailed forensic investigation offers of the crime scene offers investigators the best opportunity of gleaning crucial information and evidence which may lead to the solving of the case. Investigators also need to take full advantage of the range of specialist services available to them3COLLECTING 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 microscopephysical evidence comprises of all objects and material found in connection with an investigation that are instrumental in discovering the factsthe 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 2011LOCARDSPRINCIPLE OF EXCHANGEEdmond 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 sceneThis 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 2011FORENSIC INVESTIGATIONA 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 caseInvestigators are advised to take advantage of the full range of specialist services available to themThe 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 crimeSource IMO Resolution A.1025(26) Adopted on 2 December 2009

camprosa conference 8 - 11 November 2011

CONCEPTSDNA 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 2011DNA PROFILINGFirst used in genetic research & determining paternity cases in the 1970s1985 Dr Alec Jeffreys,Univ.of Leicester, England published on identification of individuals on basis of DNA1987 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 2011CASE STUDY : WORLD TRADE CENTRE MASS MURDER, SEPTEMBER 11,20012,823 victims1.2 million tons of debris processed1,400 vehicles parked within scene processedDestroyed 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 2011Sources and location of DNAEye glasses due to sweat or skin cellsTape or ligature due to skin cells, saliva or hairDental floss, due to saliva, semen or skin cellsOn a can due to salivaOn the rim of a glass due to salivaThe end of a cigarette butt due to salivaOn a washcloth, saliva, semen, hair, skin cells, bloodOn blankets,sheets,pillows,semen,hair,skin cells, bloodOn a hat,mask,bandanna,sweat, skin cells, hair, salivaClothing, hair, semen, blood, sweat (Gilbert,2004:316)camprosa conference 8 - 11 November 2011SAMPLESBlood 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 ageSamples successfully obtained from 2,400 year old Egyptian mummyCase study Titanic victims buried in Canada camprosa conference 8 - 11 November 2011SAMPLESDNA can be found in almost any cell of the human bodyCan 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 matchSmall samples of low copy DNA pose greater risk of contamination as extraneous DNA more easily mixed into and confused with suspect DNASource: Criminal Investigation, 2010, 8th edition, James N.Gilbert.Upper Saddle River, New Jersey

camprosa conference 8 - 11 November 2011COLLECTIONBODY FLUID DETECTION DOGcamprosa conference 8 - 11 November 2011

INITIAL WALK THROUGH

BRIDGE WINGcamprosa conference 8 - 11 November 2011

THE INVESTIGATION

SOURCE OF POSSIBLE EVIDENCE

camprosa conference 8 - 11 November 2011EVIDENCE COLLECTIONcamprosa conference 8 - 11 November 2011

SOURCEcamprosa conference 8 - 11 November 2011

SOURCEcamprosa conference 8 - 11 November 2011

SOURCEcamprosa conference 8 - 11 November 2011

FORENSIC EVIDENCE

camprosa conference 8 - 11 November 2011DNA DATABASE: SOUTH AFRICAThe South African Police Service Annual Report for 2010/2011 indicates that during the period of the report63 627 DNA samples were received for analysis100 026 DNA samples were analysed92% of DNA samples were analysed within 35 daysBiology 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 2011SOUTH AFRICAN POLICE SERVICEThe 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

MALMO DECLARATION

INTERNATIONAL CONFERENCE ON PIRACY AT SEA 17 19 OCTOBER 2011, MALMO,SWEDENThe 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 crimecamprosa conference 8 - 11 November 2011IN CONCLUSIONMost significant breakthrough in forensic science since the development of fingerprintsDNA can identify an individual to a certainty of one in a trillionDNA has demonstrated the innocence of a significant number of accused suspectsUsed to solve cold casesCan be used to create data base similar to national fingerprint systemSource: Criminal Investigation, 2010, 8th edition, James N.Gilbert.Upper Saddle River, New Jerseycamprosa conference 8 - 11 November 2011