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 may only tell the court what they saw or heard or otherwise witnessed, and not what someone else told them about what happened. This is hearsay evidence. Hearsay evidence cannot be used to establish (prove) the content of an out-of-court statement.

For example, a witness can tell the court "I saw Jill push Jack down the hill" and this can be used as evidence to establish that Jill did in fact push Jack down the hill. A witness may not be called to say "I wasn't there at the time, but Tom Piper told me that he saw Jill push Jack down the hill". Tom Piper should instead give evidence of his observation and recollection, and this can then be tested by the defendant's lawyer.

Whether particular evidence is hearsay or not is often a difficult question to answer. This is a complex area of law and there are many exceptions to the general rule, such as admissions or statements against self-interest, and certain statements made by persons who have since died and are unable to give evidence.

Changes introduced into the Evidence Act 1929 (SA) on 16 December 2024 now permit an Aboriginal person to give evidence about the traditional laws and customs of an Aboriginal group even where such evidence would otherwise be inadmissible as hearsay evidence [Evidence Act 1929 (SA) s 34ZA(a)].

Generally, the opinion of a witness is not admissible unless the witness is an expert in the field in which the opinion is given. A doctor may be able to give an opinion as to 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 court rules (for example, the Joint Criminal Rules 2022 (SA)) and laws surrounding expert opinion evidence and what is allowed by the courts. In particular, it must 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 may 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.

Changes introduced into the Evidence Act 1929 (SA) on 16 December 2024 now permit an Aboriginal person to give evidence about the traditional laws and customs of an Aboriginal group even where such evidence would otherwise be inadmissible as opinion evidence [Evidence Act 1929 (SA) s 34ZA(b)].

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.

The High Court of Australia in Nguyen v The Queen[HCA] 2020 held that prosecution's obligation to put a case fully and fairly requires tender of records of interview containing mixed statements (inculpatory and exculpatory statements). The prosecution's obligation of fairness in the conduct of a trial requires the tender of mixed statements unless there are good reasons not to do so. Where the reliability or credibility of the evidence is demonstrably lacking, the prosecutor may be justified in refusing to tender such evidence.

Historically, a person could not be compelled to testify against their spouse. 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)].

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 given to courts is divided into sworn evidence and unsworn evidence. Sworn evidence is given when someone takes an oath or makes an affirmation before giving evidence [s 4 Evidence Act 1929 (SA)]. Unsworn evidence is evidence that is given without the obligation of an oath first being taken or an affirmation being made.

Children are able to give sworn evidence to a court, if they have a sufficient understanding of the obligation to be truthful involved in giving such sworn evidence. Even if a child cannot give sworn evidence that child may be allowed to give unsworn evidence. To give unsworn evidence a person must have a proper understanding of the difference between the truth and a lie, understand the importance of telling the truth and say to the Court that they will tell the truth when they give their evidence.

To give sworn evidence the person must have the understanding needed to give unsworn evidence but in addition must understand that in giving sworn evidence they acknowledge and accept the solemnity of taking an oath/ making an affirmation and the moral and/or legal sanctions that would follow if they fail to comply with the promise to tell the truth [s 9(1) Evidence Act 1929 (SA)].

Where unsworn evidence is given the judge must tell the jury the reason why the evidence was unsworn as opposed to sworn evidence and would almost always be required to warn the jury that they need to be cautious in deciding whether to accept it [s 9(4) Evidence Act 1929 (SA)].

Section 9 of the Act does not apply to a statement made outside of court admitted as evidence under an exception to the rule against hearsay at common law or under the Act.

Special arrangements for protection

Under section 13A of the Evidence Act 1929 (SA) there are a range of special arrangements which may be made for the protection of vulnerable witness when giving evidence in criminal proceedings.

For the purposes of accessing these protections, a vulnerable witness includes a witness who is [s 4]:

The court must order special arrangements be made for a vulnerable witness if an application is made and the necessary facilities are readily available and practical and the arrangements can be made without prejudice to any other party [s 13A(1)].

The court may make a wide variety of orders such as that [s 13A(2)]:

There are some limitations and conditions to making of special arrangements set out further in section 13A of the Evidence Act 1929 (SA) [e.g. ss 13A(4)-(5c) and (11)].

In some circumstances an order may also be made for the evidence of a witness to be admitted in the form of an audio visual record, see Evidence through audio visual record below.

Child sexual offences

If an order has been made under section 13A in relation to a witness in the trial of a child sexual offence, the court may also give directions about the manner and duration of questioning, questions that may or may not be put to the witness, allocating questioning topics where there are multiple accused, the use of models, plans, body maps or similar aids to communicate questions and answers, not leading evidence that challenges the witness in cross-examination [s 13A(14)].

Under section 13C, in the case of a vulnerable witness who is the alleged victim of a child sexual offence, the court must order that an audio visual record be made of the witness’s evidence before the court (unless an order has already been made under section 12AB(2)(a) for a pre-trial special hearing or as set out above under 13A(2)(b) [s 13C(1)].

In proceedings for a domestic violence offence, where a victim of a domestic violence offence is 16 years or older and not cognitively impaired, a prescribed recording (either audio or audio visual) may be admitted into evidence under section 13BB of the Evidence Act 1929 (SA). Similar requirements generally apply as those under section 13BA of the Evidence Act 1929 (SA) (concerning evidence of vulnerable witnesses through audio visual record), namely that [s 13BB(2)(a)]:

However, even if these requirements are not satisfied, the Court may admit the evidence if satisfied that the interests of justice require it [s 13BB(2)(b)].

Unless the Court orders otherwise, an application for admission of record of evidence under s 13BB of the Evidence Act 1929 (SA) must be made via a Form 92A Interlocutory Application, and the application must be made by the date fixed for filing the relevant case statement [Joint Criminal Rules 2022 (SA) r 39.1(1)(f), 102.1].

The complainant can only be further examined, cross-examined or re-examined if there is new information that has come to light since the recording was made, the complainant gives additional evidence at the trial apart from the recording or it is otherwise in the interests of justice to allow further examination, cross-examination or re-examination [s 13BB(6)]. The prosecution may also cross-examine the complainant on some matters with the permission of the Court [s 13BB(5)].

If the Court admits evidence in the form of a recording, the judge must warn the jury not to draw from the admission of evidence in the form of the recording any inference adverse to the defendant, and not to allow the admission of evidence in that form to influence the weight to be given to the evidence [s 13BB(8)].

A domestic violence offence is any offence involving domestic abuse within the meaning of the Intervention Orders (Prevention of Abuse) Act 2011 (SA).

A prescribed recording is a recording made by a police officer when a victim is questioned by a police officer in connection with the investigation of a domestic violence offence [s 13BB(10]. The recording must have occurred as soon as practicable after the commission of the offence being investigated, the recording must be made with the informed consent of the victim and within the recording the victim must state their age, that what they say in the recording is the truth, and anything else required by the regulations or rules of court. Informed consent is taken to be given if the police officer tells the complainant that they are recording the complainant and that the recording may be used in court and the complainant indicates ( by words or conduct) that they consent to the making of the recording [see Evidence Regulations 2022 (SA) reg 4(6)]. A lack of objection to a recording may constitute consent [reg 4(7)].

If a party seeks to rely upon a recorded interview pursuant to section 13BB of the Evidence Act 1929 (SA),it must make an interlocutory application using the prescribed court form, and comply with the relevant time frames and procedures as outlined in the Joint Criminal Rules 2022 (SA). If an order is made for admission of an audio visual record, the applicant must file and serve an electronic copy of the transcript of the audio visual record at least 14 days before the trial date [Joint Criminal Rules 2022 (SA) r 130.2(4)].

If a language other than English is used in the recording, the statements must be translated into English (either in the recording or in a transcript later) and any transcript provided to the defendant or the court together with the recording [Evidence Regulations 2022 (SA) reg 4]. An interpreter’s affidavit is required as to the accuracy of the translation and the Court may require further verification.

The recording may be treated as sensitive and access may be restricted under the Evidence Act. Anyone who has possession of, or access to, recorded evidence must not allow access by another person except for the purposes of the proceedings, by a public official for the purposes of official functions or as may be authorised by the police officer who made the application for the intervention order or its variation. It is an offence to refuse or fail to comply with these requirements [reg 4(5)].

Part 3 Division 4 (sections 34U-34Z) was inserted into the Evidence Act 1929 (SA) on 29 March 2021.

If a defendant asserts that an offence occurred in circumstances of family violence [as per s 34V], a court may receive evidence of family violence [s 34W], including expert evidence consisting of social framework evidence about family violence [s 34X].

A defendant (or any other person) can adduce social framework evidence (through expert evidence), where the defendant asserts the offence occurred in circumstances of family violence, and for which one or more of the following defences are raised:

If evidence of family violence is admitted in the course of the trial for an offence that the defendant asserts occurred in circumstances of family violence [see s 34V], the judge must (whether or not sitting with a jury) identify and explain the purpose for which the evidence may, and may not be used [s 34Y].