It is an ancient rule of the common law that opinions, inferences or beliefs of witnesses are irrelevant and inadmissible as evidence to prove material facts. Out of necessity, an exception to this general rule emerged relatively early, making an expert’s opinion admissible on subjects requiring special expertise. A witness swears to what he has heard or seen or to what has fallen under his senses. The court, in arriving at a decision, infers and concludes from the testimony of such witnesses, by way of informed reasoning, rationalisation and application of rules. But there arise matters about which the ordinary degree of knowledge and experience of the court is insufficient to enable it make all the necessary inferences. Under such circumstances, the requisite knowledge and experience must be supplied to the court. This makes expert witness testimony expedient. However, with the unprecedented rise in modern scientific techniques in forensic evidence, we come to see the emergence of ambitious scientists, self-acclaimed, or designated experts and aggressive claimants, to the extent that Forensics earlier treated as gospel in the courtroom has been proven to be anything but fool-proof. Across the globe, the criminal justice system is grappling with the fallout from decades of faulty analysis in criminal cases that may have resulted in thousands of wrongful convictions.
This Course sheds light on the principles and knowledge needed to understand expert testimony in its proper perspective especially in this current dispensation where the trial judge must determine whether the expert testimony is relevant to the task at hand and whether it rests on a reliable foundation to the extent that conclusions drawn from it must be based on legitimately sound scientific and forensic methodology. The following modules speak to the issues of digital forensic expert witness in court.