Rules of Evidence
Credibility - Exceptions
Section 103 allows evidence as to credibility to be considered if it comes out during cross examination of a witness. This exception only stands where the evidence will have a substantial effect upon the witness’ believability. That is, where evidence about a witness or another person is of real concern as to their believability, not evidence of little concern. This leaves the credibility rule as excluding evidence from a witness with the sole or predominant intention or undermining another witness. If a witness has nothing substantive to say other than their unbelief in the other witness then the court will not hear it.
There are sub-sections in s 104 requiring, disallowing, or waiving the need for, the leave of the court to adduce credibility evidence of certain types. For an investigator gathering evidence the best approach is to obtain all relevant and substantive credibility evidence so that it can be brought forth at court at the proper time.
Cross examination occasions not only the questioning of a witness as to their credibility, but also an opportunity for a witness to deny the allegations put. Under section 106, once denial has occurred the other party may adduce evidence to rebut those first allegations. This means that there is value in obtaining evidence supportive of a witness’ credibility in anticipation of allegations against it.
Credibility of Persons who are Not Testifying
Where a representation of some kind is adduced in evidence, but the person who made it is not called as a witness, a party may wish to furnish evidence as to the source’s credibility. Such evidence is inadmissible under section 108A unless it has substantial effect on the source’s credibility. This would be of the order of a conflict of interest, an intellectual difficulty, or suchlike.
Persons with Specialised Knowledge
The credibility of a witness who has profound allegations may come into doubt when their allegations are difficult for a judge or jury lacking expertise in such matters to understand. An expert witness can be called subject to section 108C to give their expert opinion as to the realism of the allegations. Beale notes the relevance of this rule to cases concerning sexual offences and the emotional effects of a sexual crime. It would be relevant in any case where the aggrieved party alleges serious emotional trauma of a kind not commonly experienced, and is thus vulnerable to assumptions of exaggeration.
For a witness to qualify as a person whose evidence is exempt under s 108C, the witness must have specialised knowledge based on the person’s training, study or experience, and their opinion is based wholly on such, and will have substantial effect on the witness’ credibility.
Beale, op cit 3, p20.
 Beale, Christopher W, QC, Pocket Evidence Law, Foley’s List, Melbourne, 2014, p20.
All statutory sections from unspecified Acts, are sections from a model Act of the Commonwealth Parliament as described on the first page of this chapter, and should be replicated as described in each of the related Acts of each State and Territory. (Jurisdiction to regulate the rules of evidence exists in the States and Territories and not in the Commonwealth).