Other Admissibility Rules

Rules of Evidence

Evidentiary rules exist to allow courts to exclude any evidence that otherwise would be admissible, for reasons of general concern. The exclusions are addressed as follows:

Prejudice, Confusion and Waste of Time

Section 135 provides that where the probative value of the evidence is outweighed substantially by certain problematic issues then such evidence is to be excluded. These issues are a tendency to produce unfair prejudice, a potential to be misleading or confusing, or an undue waste of time. Misleading and confusing evidence includes evidence which fails to present the whole picture of a set of facts, as shown in Hughes Aircraft v Airsercvices Australia.

Probative value is to be determined in broadly the same manner as discussed above under the heading of Tendency and Coincidence. However, it has been noted:

The probative value of hearsay evidence could be affected by the circumstances in which the representation was made and the opportunity to test the weight of the evidence.... The possibility of concoction could suggest contamination.

Evidence Obtained Improperly or Illegally

Any evidence which was obtained in a manner that contravenes any Australian law, or by ‘improper’ means, may be deemed inadmissible under section 138. Also disallowed potentially is evidence obtained ‘in consequence of an impropriety or contravention of an Australian law.’ Inadmissibility is not automatic, but follows consideration as to whether reasons for admitting it outweigh the reasons against, given the manner in which it was obtained.

Specific rules exist in sub-section 2 in relation to evidence of admissions where an admission is deemed to have been obtained improperly if any of two things occurred during questioning of a person:

Anything was done or omitted during questioning which the questioner ought to have known was likely to impair the ability of the person being questioned, to respond rationally;
A false statement was made during questioning which the questioner ought to have known was likely to elicit an admission.

Impropriety includes the conduct described in sub-section 2. Impropriety is further defined in s 139, which relates to police procedures and is of no relevance to civilian law enforcers. It is not open to courts to import whole new concepts into the definition of statutory wording when there is sufficient material to establish a clearly defined range of meanings. Because there is nothing to suggest that courts can stretch the meaning of impropriety to include the moral standards or preconceptions of the presiding judicial officer, it is not anticipated that courts will take any sort of expansive view of what amounts to impropriety.

Courts do permit a certain amount of trickery and subterfuge on the part of police. This is especially so when dealing with the technique of a fake gang comprised of undercover police who coax a suspect into confessing to a past crime thinking he will be allowed into a lucrative gang membership or escape the spectre of a re-opened police investigation. An example is to be found in McDermott v R. Courts have for a long time ruled against forms of pressure and deception that affect the suspect’s ability to give evidence voluntarily but that is as far as they have gone with police.

Nevertheless in Waverley Council v Tovir Investments evidence obtained through undercover surveillance by a private investigator in a residential premises was ruled to have been obtained improperly. An investigator was contracted by Waverley Council to obtain evidence of the use of certain allegedly residential properties were being used as backpackers’ hostels. The method to be used was to pose undercover as a backpacker seeking accommodation while filming the events covertly. The reasons for the ruling included factors that raise suspicion of an attempt by the Council to circumvent existing laws that would prevent them from obtaining the same evidence, but the fact of undercover operations also had some effect. Factors on the side of propriety related mostly to the need to enforce obedience to a court order. It was also considered that any breach of law was inadvertent rather than deliberate. On balance it was ruled to be improperly obtained but was admitted due to its probative value. For detailed reasons, see the judgement, paragraphs 74 to 77. It appears that this judgment applies a highly expansive reading of sub-section 2, paragraph b (quoted above) which makes pretext-based investigations improper, and potentially pointless.

Sub-section 3 lists a range of matters that the court can have regard to when determining admissibility. The list is not exclusive. These include, among others, the probative value of the evidence and its importance to the matter, the nature of the issues in question, the difficulty of obtaining evidence other ways, and the gravity and intentionality of the contravention or impropriety.

Investigators need to be aware that if a law was broken in the course of obtaining evidence, then the evidence is of no benefit. Therefore any risk of legal action or prosecution incurred in the course of an enquiry, which might otherwise be thought worthwhile for the sake of the client, is likely to yield no benefit. A civilian person investigating a criminal matter may, due to the likely gravity of the matter and the fact of them acting alone, be able to persuade a court that it is desirable to indulge a minor infraction. However, a civil matter is not often as serious and a court therefore may be resistant to allowing evidence obtained in conflict with s 138.

Evidence from Persons of Lesser Capacity

Evidence sometimes needs to be sourced from persons of reduced capacity to testify. Minors, the aged and the mentally unwell, may need to be approached for evidence due to having first hand knowledge or due to having contributed to a certain document.

Minors

Under the Uniform Evidence Law, children of any age are allowed to give evidence as long as they understand the obligation to tell the truth and feel able to contradict a false statement. However they must be provided with a support person in interviews. The support person may be required by the applicable legislation to be a parent or guardian or some sort of independent person.

Age and Mental Illness

Evidence law with respect to the aged and the mentally unwell differs in that it is presumed to be unreliable unless proven to be reliable. See for example the Commonwealth’s model evidence act, s 165(1)(c). It is therefore undesirable to interview such persons unless there is ample reason to consider them reliable in what is actually said. The provision of a support person is mandatory during interviews.

Hughes Aircraft Systems International v Airservices Australia (1997) 146 ALR 1.

Northern Territory Government, Department of Justice, Discussion Draft of the Uniform Evidence Act for the Northern Territory, Darwin, 2011, p 93.

McDermott v R (1948) Unreported, HCA, 23 Aug & 22 Sept 1948.

Waverley Council v Tovir Investments Pty Ltd and Rappaport (No 2) [2013] NSWLEC 21.

Evidence Act 1995 (Cth), s165(1)(c)