An alibi is used to show that the defendant could not have committed the crime because she or he was not at the scene of the crime when the offence was alleged to have been committed, but rather, was somewhere else.

This evidence may be given by the defendant and by other witnesses on the defendant's behalf.

Under s 124 of the Criminal Procedure Act 1921 (SA) if a defendant proposes to introduce evidence of alibi at the trial of an indictable offence in the Supreme Court or the District Court prior notice of the proposed evidence must be given, which is filed at the same time as the defence case statement is filed. This is not required if the essentially the same evidence was given at the preliminary examination where the defendant was committed to trial [s 124(3)].