In criminal proceedings in which a person is charged with a sexual offence, evidence may not be introduced, and questions may not be asked, about the alleged victim's sexual reputation [Evidence Act 1929 (SA) s 34L(1)(a)]. Unless the trial judge orders otherwise, an alleged victim may only be asked questions about their sexual activities before or after the alleged offence if the questions relate to recent sexual activities with the accused [s 34L(1)(b)].

In certain circumstances, the judge may allow an alleged victim to be cross-examined on their sexual activities with people other than the accused. In deciding whether to permit such questioning, the judge must bear in mind that alleged victims should not be subjected to unnecessary humiliation, distress or embarrassment. The admission of such evidence must be in the interests of justice. The trial judge must also consider whether the evidence that might be elicited in such cross-examination is of substantial probative value and also whether it might impair the credibility of the alleged victim [see s 34L(2)].

Corroboration is confirmation (or backing up) of an aspect of a witness's evidence by other independent evidence. In a trial for sexual assault, this might be the findings of a doctor who examined the victim, torn or stained clothes worn by the victim, or the evidence of an eye witness. In the past, a judge had to tell a jury that it was unsafe to convict a person based on the uncorroborated evidence of the victim (Kelleher v The Queen (1974) 41 CLR 534). A judge is no longer required to issue this warning [Evidence Act 1929 (SA) s 34L(5)] but in appropriate cases judges still do.

In a trial where more than one offence is charged, the trial judge is no longer permitted to direct the jury that if the jury doubts the truthfulness or reliability of the alleged victim's evidence in relation to one charge, that doubt must be taken into account in assessing the truthfulness or reliability in relation to other charges, or in general [s 29B].

Broadly speaking, the law of evidence does not permit a witness to describe statements made by other people if that evidence is meant to show that what that other person said was true (known as hearsay). An exception to this rule is that a witness may, in certain circumstances, give evidence of what an alleged victim said very soon after an alleged sexual attack. This is known as evidence of recent complaint [s 34M(3)]. However, a jury can only ever use it as proof of the fact that a complaint had been made and evidence of consistency with the alleged victim and not as truth of what the words of complaint actually described [s 34M(4)].

In a trial of a sexual offence charge where consent is in issue, the judge must give certain directions to the jury as apply to the case, including [s 34N]:

The court may also receive expert evidence addressing issues of consent [s 34N(2a), see also Criminal Procedure Act 1921 (SA) s 124].

Some out of court statements made by certain alleged victims of sexual offences are admissible and may be used to prove the truth of the facts asserted in that statement. This is only where the alleged victim is a child 14 years or younger, or a person with a disability that adversely affects their capacity to give a coherent account of their experiences or respond rationally to questions. Further conditions apply before such evidence will be admitted [see Evidence Act 1929 (SA) s 34LA].

See also Evidence of vulnerable witnesses.