Unanswered questions for Brent and David Tong

By Anna Sandiford 04/10/2011


I apologise – I have neglected to answer questions about my book, Expert Witness, which was recently given away by Sciblogs and that Grant Jacobs reviewed
Some more questions are as follows:

Does forensic science only refer to science used for court cases, or are there other forms of investigation to which it pertains? Brent

I mention this in one of the chapters because this is quite a common question.  The term ‘forensic’ relates specifically to the court so technically forensic science relates to science presented in court.  However, the term ‘forensic’ is regularly misused and is generally taken to mean ‘science’ whereas anything, in theory, can be presented as evidence in court, i.e. be ‘forensic’, as long as it is relevant to the case in question and it is accepted by the courts as appropriate.

The usual tests I apply are:

  • whether or not something is relevant and reliable,
  • the information is more probative than prejudicial, and
  • whether it substantially assists the trier of fact (judge/jury).

Do you follow the outcomes of the cases you have worked on? Do you ever think the Judge, jury or counsel must have totally misunderstood you? David Tong

No, I don’t generally follow the outcomes of the cases in which we have been involved.  As an Expert Witness, our duty is to the court so whether or not the defendant is found guilty or not guilty is not of professional interest to us.  What is important is whether or not our work was understood by the Court and it can be very difficult to know whether or not it was.  The best assessment is your own assessment of the judge’s/jury’s reaction to your evidence, any questions they ask and also the line that cross-examination takes.

I have given evidence in alcohol-related cases in the past when the barristers for both the Defence and the Crown (in separate cases) have not understood my evidence but it was clear from the jury’s faces and the judge’s prompts that they all understood it.  If the lawyer doesn’t understand it and the court does then the court asks the lawyer to move on — and in one case, the judge basically said it was tough luck if the lawyer didn’t understand it because he wasn’t the one making the decision on the Ultimate Issue (guilty or not guilty), it was the court making that decision and the court understood it so move on to the next question!

When I worked in England and Wales it was extremely rare to be advised of the outcome of a case unless it was reported in the media.  In New Zealand, barristers are more likely to let us know the outcome.  We should also be notified if a case goes to Appeal because we will maybe required for it.