First generation forensic evidence and its influence on legal decision-making: a South African perspective

Abstract

English: Interactions between science and law can be dated back as far as 9000 B.C. to 3000 B.C., to a time known as the Neolithic age. By the seventeenth century, great scientific contributions by, amongst others, Copernicus, Galileo, Newton, and Boyle affected the way the world was viewed and what methods were most appropriate for finding the truth and, specifically, altered the thought processes of the entire literate English society, including English jurists. During the seventeenth century in England, the fields of law and science enjoyed increased awareness of the probability of truth, not the certainty of it. The search for absolute truth was thus replaced by probabilistic hypotheses and assessment of evidence to achieve truth beyond a reasonable doubt. The interconnectedness of science and law has diminished over time as contemporary thinking demanded not only greater specialisation in the profession and its subdivisions, but also a greater autonomy of legal thought and reasoning. Practitioners, scholars and authors held the view that legal reasoning is, and should remain, separate from scientific reasoning. Modes of reasoning employed in criminal investigation and judicial decision-making are communal in both science and law. Additionally, investigating officers frequently employ forensic science and scientific evidence to assist and direct them in criminal investigations. In the same manner, prosecutors apply forensic evidence in order to assist the court in finding the truth, and to ultimately prove its version of criminal events. In South Africa, police investigators and state prosecutors typically rely on eyewitness testimony in both the detection of crime and to achieve successful conviction of guilty offenders. In addition, DNA evidence has emerged as the golden standard of forensic evidence and much reliance is placed on the results of DNA profiling. However, eyewitness testimony is notoriously unreliable and DNA evidence is not the infallible assurance of certainty it was once thought to be. It is trite that presiding officers must be provided with all relevant and admissible evidence in criminal trials. This includes traditional forensic sciences like bloodstain pattern analysis, trace evidence, fingerprint evidence and many more. Recent research has revealed the questionable scientific foundations of these traditional forensic sciences. While the scientific community is working towards stabilising these knowledge bases, provisions of the law of evidence must provide adequate instruments to prevent the admission of ‘junk’ science into evidence. Yet an examination of a variety of rules of admissibility reveals a deficiency in the law to competently exclude fallible and unreliable forensic evidence. In the South African criminal justice system presiding officers invest great reliance on the opinion and explanation of expert witnesses without critically assessing the scientific validity of the testimony. This has resulted in the admission of faulty evidence. To mend this problem presiding officers, as well as investigating police and legal practitioners must obtain a solid scientific knowledge base to enable these role-players to accurately assess forensic evidence.

Afrikaans: Interaksies tussen wetenskap en die reg dateer terug so ver as 9000 tot 3000 V.C. na ‘n tyd bekend as die Neolitiese periode. Teen die sewentiede eeu, het wetenskaplike bydraes deur onder andere Copernicus, Galileo, Newton, en Boyle die manier wat ons die wêreld beskou verander en nuwe dimensie gegee aan die metodes wat mees effektief sal wees in die soeke na waarheid. Dit het ook veranderinge meegebring in die denkprosesse van die deursnee geletterde Engelse gemeenskap, insluitend Engelse juriste. Tydens die sewentiende eeu in Engeland, het wetenskap en die reg meer bewus geword van die waarskynlikheid van die waarheid in kontras met die sekerheid daarvan. Die soeke na die absolute waarheid is mettertyd vervang deur waarskynlikheidsteorieë en evaluering van bewysmateriaal om waarheid bo redelike twyfel vas te stel. Die intieme verhouding tussen die wetenskap en die reg het met tyd verslap soos moderne denkpatrone noodwendig groter spesialisasie in die professies en hul onderafdelings, asook die noodsaaklikheid van groter onafhanklikheid van beide wetenskaplike en regsfilosofieë, geëis het. Wyses van beredenering wat toepassing vind in misdaadondersoek en geregtelike besluitneming stem ooreen in beide wetenskap en die reg. Daarenbowe gebruik ondersoekbeamptes gereeld forensiese wetenskap en wetenskaplike bewyse om hul by te staan in misdaadondersoek. Staatsaanklaers gebruik op hul beurt forensiese bewyse om die hof by te staan in feitebevindings, asook om die vervolging se weergawe van ‘n misdaadinsident te staaf. In Suid Afrika steun ondersoekende polisiebeamptes en staatsaanklaers swaar op ooggetuie verklarings en getuienis in beide misdaadondersoeke asook die verkryging van skuldigbevindings. Die resultate van DNA analise is ook wesenlik belangrik in strafregtelike vervolging en verteenwoordig die goue standaard van forensiese getuienis. Ooggetuie verklarings en getuienis is egter berug as onbetroubare bron van inligting en DNA bewyse is nie so ‘n absoluut onfeilbare bron van sekerheid as wat eens geglo is nie. Dit is gemene saak dat voorsittende beamptes van alle relevante en toelaatbare getuienis voorsien moet word in strafregtelike verhore. Dit sluit die tradisionele forensiese wetenskappe soos bloedspatselanalise, spoorelement analise, vingerafdrukgetuienis en vele meer in. Onlangse navorsing het die twyfelagtige wetenskaplike grondslag van hierdie tradisionele forensiese dissiplines ontbloot. Terwyl die wetenskaplike gemeenskap tans werk om hierdie grondslag te stabiliseer, is dit die plig van die bepalings van die bewysreg om geskikte instrumente daar te stel om die toelating van onbetroubare wetenskap te voorkom. ‘n Ondersoek van die verskeie toelaatbaarheidsreëls toon egter dat leemtes bestaan in die reg om howe genoegsaam teen onbetroubare en foutiewe getuienis te beskerm. In die Suid Afrikaanse regsisteem plaas voorsittende beamptes groot vertroue in die opinie en verduideliking van deskundige getuies, sonder om die geldigheid van die wetenskap krities te bevraagteken. Dit veroorsaak die periodiese toelating van foutiewe getuienis. Om hierdie probleem aan te spreek moet voorsittende beamptes, ondersoekende polisiebeamptes, asook regslui ‘n behoorlike grondslag in wetenskaplike kennis opdoen om hulle in staat te stel om forensiese getuienis met akkuraatheid te evalueer.