Seyisi v The State

The appellant, Nomfusi Nompumza Seyisi, was charged in the Mdantsane Regional Court with 1025 counts of fraud, alternatively theft, for allegedly causing unauthorised payments of social welfare grants to fictitious persons by affixing her own thumb and/or toe prints to payment vouchers. She was employed as a paymaster by the Department of Social Development, Bisho, Eastern Cape, during the period 1994 to 1996. An investigation by fingerprint expert Mr Stassen revealed that some beneficiaries reflected in the system were either dead at the time of payment or recorded twice, resulting in duplicate payments. Stassen compared fingerprints and toe prints on 1025 payment vouchers with the appellant's prints and found seven or more points of similarity on each print, concluding they emanated from the same person. The appellant was convicted on all counts, sentenced to five years imprisonment, and ordered to pay R1,334,820 to a curator bonis appointed under POCA. She appealed to the Bisho High Court against the convictions, which was dismissed. She then appealed to the Supreme Court of Appeal against convictions only.

• Whether fingerprint expert evidence that is accepted as credible constitutes prima facie proof of the facts it establishes
• Whether the trial court erred in accepting expert fingerprint evidence without requiring detailed explanation of the points of similarity
• Whether the defence bore an onus to rebut prima facie expert evidence once accepted as credible
• Whether the conviction based on expert fingerprint evidence was properly founded in the absence of a challenge to that evidence

The appeal was dismissed.

Expert evidence, once accepted as credible, constitutes prima facie proof of the facts it establishes. In the absence of a challenge to expert evidence that prima facie establishes the relevant facts, a court is entitled to rely upon it to convict. Where expert evidence is presented and accepted as credible, an onus rests on the defence to rebut or dispute the facts prima facie proved by that expert evidence. A court is not obliged to require detailed explanation of the technical basis of expert opinion or to personally verify the expert's conclusions where the expertise is not challenged and no rebuttal evidence is led. The failure by the defence to cross-examine an expert witness on technical matters or to lead contradictory expert evidence results in the expert evidence standing as undisputed and proven.

The court noted with approval that expert witnesses are in principle required to support their opinions with valid reasons, but observed that no hard-and-fast rules can be laid down, as much will depend on the nature of the issue involved and the presence or absence of an attack on the opinion of the expert. The court observed that where an expert has personally conducted experiments it is easier for the court to follow the evidence, accept it and rely on it. The court commented that the reason for the defence's failure to recall the expert witness for further cross-examination after reserving that right was 'obvious', implying that consultation with their own expert would have confirmed the State expert's conclusions.

This case is significant in South African criminal law and evidence law for establishing the evidentiary weight and treatment of expert evidence. It confirms that once expert evidence is accepted as credible, it constitutes prima facie proof of the facts it establishes, and the onus then shifts to the defence to rebut that evidence. The case clarifies that a court is not required to independently verify or personally satisfy itself of the technical details underlying expert opinion where that opinion is not challenged by the defence. It reinforces that the failure to challenge credible expert evidence or to lead rebuttal evidence will result in that evidence being accepted as proven. The case provides important guidance on the tactical obligations of defence counsel when faced with expert evidence, particularly in fingerprint identification cases. It also demonstrates the application of POCA confiscation orders in fraud cases involving public funds.