Beware the hired gun expert witness
22 May 2019 00:00
An expert witness should never assume the role of an advocate and should refrain from giving evidence beyond the scope of the field from which he or she yields.
There was much media coverage of Jason Rhode, who was convicted of murdering his spouse, with stories of his mistress during a sensational and eventful trial. The conviction judgment does, however, highlight two important parts of our law.
- The first is that attempts to cover up a crime, in this case by staging a murder to look like a suicide, can amount to an additional crime of “Defeating or obstructing the administration of justice”.
- The second point is that expert witnesses must remember that they are called to testify to assist the court and they must remain unbiased and true to their disciplines and expertise.
With reference to the paragraph in this judgment called “Beware the hired gun” where the court emphasizes that the expert must guard against buckling to the hype and demands which comes with litigation. The expert must not present a product tailored to suit the party who calls for his or her expert opinion. An expert witness should never assume the role of an advocate and should refrain from giving evidence beyond the scope of the field from which he or she yields.
Expert witnesses in criminal cases have long been a tricky issue, see the cases referred to in S v Rhode and also see the Index to South African Criminal Cases 1910 – 2018. The S v Rhode case will make a valuable addition to case law on this topic.
Download the judgment here as reported in the All South African Law Reports.