Malicious prosecution 

Malicious prosecution allows a person wrongly subjected to criminal process to sue the person who set it in motion. It is deliberately difficult to establish, and the difficulty is principled: prosecutors and complainants must be able to act on an honest and reasonable view of the facts without fearing suit if the prosecution fails. An acquittal, standing alone, proves nothing about the propriety of bringing the charge.

The four elements

A v New South Wales (2007) 230 CLR 500 is the governing Australian statement.¹ The plaintiff must prove:

1. that the defendant initiated or maintained a prosecution against them;
2. that the prosecution terminated in the plaintiff's favour;
3. that the defendant acted without reasonable and probable cause; and
4. that the defendant acted maliciously — for a purpose other than the proper invocation of the criminal law.

Damage is generally treated as flowing from the character of the proceedings themselves, since a criminal prosecution is taken to injure reputation, or from the loss actually suffered.

Initiating or maintaining a prosecution

The defendant must have been actively instrumental in setting the law in motion. Merely giving information to police, honestly and without pressure, is not enough: the decision to charge is the prosecutor's. Liability attaches where the defendant procured the prosecution — by supplying information they knew to be false, by withholding what they knew undermined it, or by exerting influence such that the prosecutor's independent discretion was displaced.

A defendant may also be liable for maintaining a prosecution: continuing it after learning information that removes the reasonable and probable cause that existed when it began.

Termination in the plaintiff's favour

Acquittal, a discontinuance, or a withdrawal will suffice. What will not is a termination that leaves the merits unresolved in the plaintiff's favour, or a conviction that stands. The requirement exists because the tort must not become a means of relitigating guilt in a civil court.

Absence of reasonable and probable cause

This is the element that defeats most claims, and it is unusual: the plaintiff must prove a negative, and must do so as at the time the prosecution was begun or maintained, not with hindsight.

The inquiry has two limbs. Subjectively, did the prosecutor honestly believe the case was a proper one to lay before a court? Objectively, was there sufficient material to justify that belief in a reasonable person in the prosecutor's position? Both must fail for the element to be made out. A prosecutor who honestly but unreasonably believed the case was good, or who had ample material but did not believe it, may satisfy the element — but the plaintiff must establish it, and courts require more than the fact of acquittal.

The standard is not proof of guilt. A prosecutor need only conclude that the material warrants putting the accused on trial, which is a considerably lower threshold.

Malice

Malice means a purpose other than the proper one of carrying the law into effect. Spite or ill-will will do, but so will any improper purpose — pressuring the plaintiff in an unrelated dispute, deflecting attention from the defendant's own conduct, or gaining a collateral advantage.

Malice is not established merely by proving the absence of reasonable and probable cause, although the absence of cause may, with other material, support an inference of it. The two elements are independent and both must be proved.

Related actions, and how to keep them apart

False imprisonment addresses the detention itself and requires no proof of malice or want of cause; it is the stronger claim where the plaintiff was arrested without lawful authority. Abuse of process addresses the use of regularly commenced proceedings for a collateral purpose, and does not require the proceedings to have terminated in the plaintiff's favour. Negligent investigation is not recognised as a tort in Australia, and pleading it is a common error.

Malicious prosecution has also been extended to some civil proceedings and to steps short of trial, but the extensions are narrow and should be identified as such rather than assumed.

Damage

Damage is not a separate fifth element in every formulation, but the tort is not actionable per se and the plaintiff must have suffered harm. Three heads are recognised:

• damage to reputation, where the charge was one that would injure the plaintiff's fair name;
• damage to the person, being loss of liberty through arrest or remand; and
• damage to property, principally the costs of defending the prosecution beyond any award recovered.

General damages for distress, anxiety and reputational harm are commonly the largest component. Exemplary damages are available where the conduct was contumelious, and are more readily awarded against a defendant who abused a public office.

Proceedings other than criminal

The tort developed around criminal prosecutions, and its extension to civil proceedings has been narrow. Australian courts have accepted that maliciously instituting certain civil proceedings — winding up, bankruptcy, and proceedings affecting reputation or property in an analogous way — may be actionable, but a general action for maliciously bringing a civil claim is not established.

The reason is that the ordinary costs order is treated as sufficient compensation for being sued without merit, and the courts are reluctant to create a satellite action in every unsuccessful case.

Related statutory and disciplinary avenues often provide a better route, and the abuse of process tort covers the case where proceedings, however well founded, were used for a collateral purpose.

Applying this in a problem question

1. Identify precisely who initiated or maintained the prosecution, and whether the police exercised an independent discretion that breaks the chain.
2. Confirm the proceedings terminated in the plaintiff's favour, and say why the form of termination qualifies.
3. Fix the time at which reasonable and probable cause is assessed, then apply the subjective and objective limbs separately.
4. Deal with malice independently of want of cause, and identify the improper purpose alleged.
5. Consider false imprisonment and abuse of process in the alternative — they are frequently the stronger claims on the same facts.

Self-check

• Have I remembered that the plaintiff must prove the absence of reasonable and probable cause?
• Have I assessed cause as at the time of the decision, rather than with hindsight?
• Have I treated malice as a separate element rather than inferring it from want of cause alone?
• Have I considered whether false imprisonment or abuse of process fits the facts better?