Section 131 of the Magistrates’ Court Act 1989 gives magistrates the power to award costs in summary criminal proceedings.
The section confers a general discretion. Though there’s nothing written there about an accused having to be acquitted before a discretion to award costs exists, an accused will usually need to be considered a successful defendant before there will be a reasonable expectation of costs: Latoudis v Casey (1990) CLR 534.
What a successful defendant is will depend on the case. In Do v Bowers (Unreported, Supreme Court of Victoria, O’Bryan J, 10 October 1996), the Court observed,
It is not unusual in the Magistrates’ Court for a defendant to contest some charges and at the end of the day be found not guilty of some and guilty of others. A defendant may be found not guilty of the most serious charge and guilty of the lesser charge arising out of the same transaction. In such circumstances a defendant would not be awarded costs as a “successful defendant” under the general rule.
Last year, Costa v Parks  VSC 47 applied a similar principle.
The accused men, Costa and Shepherd, were charged with illegal fishing on the Murray River. They were both represented by the same counsel at a contested hearing. The defence was first based on a preliminary jurisdictional argument (about whether the alleged offence occurred in NSW or Victoria). When that failed, a factual defence was put to the Court. Mr Costa entered a plea of guilty to two charges, eight were dismissed at the end of the contested hearing, and he was found guilty of one. None of the charges against Mr Shepherd were found proven.
An application for costs was made on behalf of each of the accused. The application of Mr Costa was refused, and Mr Shepherd was granted a single day’s appearance fee for counsel, and his solicitor’s preparation costs.
The Supreme Court found that, in basing a substantial portion of the defence around a jurisdictional argument that failed, neither of the accused might be considered a wholly successful defendant. Habersberger J noted that such a finding by the magistrate could invoke s 131(2A), which states,
(2A) In exercising its discretion under subsection (1) in a proceeding, the Court may take into account any unreasonable act or omission by, or on behalf of, a party to the proceeding that the Court is satisfied resulted in prolonging the proceeding.
How far this principle can stretch is unknown. If an idle preliminary argument fails it could lead to the forfeit of some proportion of costs, even if all charges against an accused are eventually dismissed. With the current emphasis on speedy case resolution, it may be that the conduct of the parties at contest mention is also a factor to be taken into account.