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In a trial, a court must decide what the facts are. A court makes its determination of what the facts are based on a consideration of the evidence that is presented to it.

Evidence is all the information given directly to the court by a witness. It must comply with particular rules. This is the only information of which the court can take notice of.

Much of the Law of Evidence relevant to South Australia is contained in the Evidence Act 1929 (SA).

Some evidence issues

Below are a few common evidence issues - however the law of Evidence has many exceptions and nuances, some of these are in the Evidence Act 1929 (SA), and some are in the common law.

Legal advice and representation is always advised for anyone charged with an indictable offence. Please see our information on Applying for Legal Aid if you are charged with an indictable offence and need legal help.

There are also more detailed overage of some of the laws of Evidence discusseed throughout the handbook in sections relevant the Law Handbook. For example on evidence of victims of child sexual assault; other sexual assault cases; on evidence of young children and some people with disabilities under Pre-trial special hearings.


Evidence must be relevant to the issue being tried.

For example, when a person is charged with theft from a house, it would be a relevant fact that the person's fingerprints were found on the windowsill of the house, but it would not be considered relevant that the person often consumed too much alcohol or came from a family of thieves.


A witness will be asked to tell the court only what she or he saw or heard, not what someone else told the witness had occurred. This is hearsay evidence.

For example, a witness can say 'I saw Jill push Jack down the hill' but cannot say 'I wasn't there at the time, but Tom Piper told me that he saw Jill push Jack down the hill'.

Whether a particular piece of evidence is hearsay or not is often a difficult question to answer, as this is a complex area of law and there are many exceptions to the general rule.


Generally, the opinion of a witness is not admissible unless the witness is an expert in the field on which the opinion is given. A doctor may be able to give an opinion on whether a particular blow may have caused the death of a person, while a non-medical witness cannot give such an opinion as evidence.

There are many rules and laws surrounding expert opinion evidence and what is allowed by the courts, in particular it has to be directly relevant to the facts in issue and the expert must have expert qualifications or experience in the relevant field.

Lay (non-expert) witnesses are able to give evidence on matters of fact, or on those things for which the experience of everyday life is sufficient, such as the weather and general identity.


Generally, the prosecution cannot ask questions of a defendant which tend to show that the defendant has a bad character or has committed other offences. However, if at the trial the defendant or the defendant's lawyer tries to attack the credibility of a prosecution witness by reference to bad conduct by that witness, the court may also allow the defendant (if she or he gives evidence) to be questioned about her or his own bad character or conduct.

The defendant is entitled to raise her or his good character as an issue at the trial and to have that evidence taken into account on the question of guilt or innocence. In this case, however, the prosecution can call evidence to rebut this to show that the defendant is of bad character.

At the trial, the decision whether to attack the character of prosecution witnesses or whether to raise the good character of the defendant needs careful consideration.


Evidence is often given that the defendant made an admission or confession of guilt. The evidence may be of a conversation in which the defendant verbally confessed or it may be a written record of questions asked by a police officer and answers given by the defendant (a record of interview). For a confession to be admissible in evidence, it must be made freely and voluntarily.

There is also the requirement that the police officers comply with Section 74D of the Summary Offences Act 1953 (SA) , recording the interview with suspects [see generally the obligations on recording interview at ss 74C-74G].

Any interview will not be admitted if it was induced by a threat, promise or untrue representation made by the police or some person in authority. The defence may object to the admissibility of a record of interview on this ground and the court will consider whether to admit it or not.

Even if a court decides that a confession is voluntary, it may be excluded if it would be unfair to the defendant to admit it. A court may also exclude a confession on the grounds of public policy. This means weighing the public interest in having offenders convicted, against the public interest in discouraging police officers from engaging in unlawful conduct during the investigation of a crime.

Evidence by a close relative

Historically, a wife could not be compelled to testify against her husband. This is no longer the case.

A close relative of a person charged with a criminal offence is regarded as competent and compellable to give evidence against that person [s 21 (1) Evidence Act 1929 (SA)]. A close relative can be a spouse, domestic partner, child or parent of the accused [s 21(9)] .

In certain circumstances a close relative who is called as a witness may be excused from giving evidence and can apply for an exemption [s 21(2)].

When considering whether to excuse such a witness, the judge must consider the risk of substantial harm to the relationship between the prospective witness and the accused and whether the witness is likely to suffer serious material, emotional or psychological harm by being compelled to give evidence.These factors have to be weighed against the gravity and the nature of the offence [s 21(3)].

A judge can grant this exemption, even where an application hasn't been made if the prospective witness is a young child (14 years old or under) or is cognitively impaired [s 21(4)].

Evidence by a journalist

Protections under Part 8A of the Evidence Act 1929 (SA), commonly referred to as shield laws, mean that a journalist cannot generally be compelled by a court to answer any question, or produce any document, that discloses the identity of a confidential informant [see section 72B of the Evidence Act 1929 (SA)].

For more information see: Laws relating to Journalists.

    Evidence  :  Last Revised: Thu Jun 16th 2016
    The content of the Law Handbook is made available as a public service for information purposes only and should not be relied upon as a substitute for legal advice. See Disclaimer for details. For free and confidential legal advice in South Australia call 1300 366 424.