Honest and Reasonable Mistake of Fact in Victoria

In Australia, criminal offences are generally categorised into three types: mens rea offences, strict liability offences, and absolute liability offences. Understanding these categories is essential when considering the availability of the defence of honest and reasonable mistake of fact.

This defence plays a critical role in strict liability offences, particularly in Victoria, where many regulatory and road-related offences fall into that category.

Mens Rea Offences

Most criminal offences are mens rea offences. In these matters, the prosecution must prove both:

• The physical act (actus reus); and
• A guilty mind (mens rea), such as intention, knowledge, or recklessness.

For example, under section 72 of the Crimes Act 1958 (Vic), theft requires proof that the accused dishonestly appropriated property belonging to another with the intention of permanently depriving the other of it. The offence cannot be committed accidentally or unknowingly, a deliberate state of mind is required.

If the prosecution cannot establish the required mental element, the accused must be acquitted.

Absolute Liability Offences

Absolute liability offences require proof only that the physical act occurred. There is:

• No requirement to prove intention; and
• No available defence of honest and reasonable mistake of fact.

The accused’s state of mind is irrelevant. If the act occurred, liability follows.

Examples may include certain regulatory offences under Commonwealth legislation such as the Customs Act 1901, as well as specific environmental or public welfare offences where Parliament has clearly excluded fault elements.

Because there is no defence available, courts interpret absolute liability provisions strictly.

Strict Liability Offences

Strict liability offences also do not require proof of intention. However, unlike absolute liability offences, a limited defence is available, the defence of honest and reasonable mistake of fact.

Strict liability offences are common in regulatory contexts, particularly under road safety legislation. For example, driving whilst suspended or driving an unregistered vehicle may be treated as strict liability offences.

Under legislation such as the Road Safety Act 1986, many offences focus solely on whether the prohibited act occurred. The prosecution does not need to prove that the accused intended to commit the offence.

However, if the accused acted under an honest and reasonable mistake of fact, they may avoid liability.

What Is an Honest and Reasonable Mistake of Fact?

An honest and reasonable mistake of fact arises where:

• The accused believed certain facts existed;
• That belief was honestly held;
• The belief was reasonable in the circumstances; and
• If those facts had existed, the conduct would have been lawful.

This defence traditionally developed at common law but has also been codified in some jurisdictions, including under section 9.2 of the Commonwealth Criminal Code.

In Victoria, in relation to state offences, the defence continues to operate primarily through common law principles.

The Three Essential Elements

To successfully rely on the defence, three elements must be established on the evidence:

1. The Mistake Must Be Honest (Subjective Test)

The accused must have genuinely held the belief at the time of the offending.

It is not enough to say:

• “I did not think about it,” or
• “I forgot.”

2. The Mistake Must Be Reasonable (Objective Test)

The belief must also be objectively reasonable in the circumstances.

This does not mean the belief must be correct. It means that a reasonable person, placed in the accused’s position and armed with the same information, could have formed the same belief.

The reasonableness assessment considers the circumstances known to the accused at the time.

3. The Mistake Must Be One of Fact, Not Law

This distinction is crucial.

A mistake of fact relates to circumstances or events.
A mistake of law relates to misunderstanding what the law says.

The defence does not apply to ignorance of the law. 

For example:

• Believing your licence was valid when it was suspended = mistake of fact.
• Knowing you were suspended but believing it was legal to drive anyway = mistake of law.

Only the first scenario may enliven the defence.

Practical Examples

Example 1: Driving While Suspended

A person drives while their licence is suspended but never received notice of suspension because the licensing authority failed to update their address despite notification.

If the accused can demonstrate:

• They updated their address;
• They received no notice; and
• They believed their licence remained valid,

then the defence may apply.

However, if the accused simply assumed their licence was valid without checking, or ignored warning correspondence, the defence is unlikely to succeed.

Example 2: Unregistered Vehicle

If a person simply forgets to renew their vehicle registration, the defence will likely fail. Forgetfulness is not a positive belief.

However, if the person paid the renewal fee and received confirmation but due to an administrative error the registration was not processed, the defence may be available.

Who Bears the Burden of Proof?

The prosecution always bears the burden of proving the offence beyond reasonable doubt.

For strict liability offences, this means proving:

• The act occurred; and
• The accused committed it.

Once the accused raises evidence of an honest and reasonable mistake of fact, the burden shifts back to the prosecution. They must then prove, beyond reasonable doubt, that:

• The belief was not honestly held; or
• The belief was not reasonable; or
• It was a mistake of law rather than fact.

If there remains a reasonable doubt, the accused must be acquitted.

When Is the Defence Available?

The defence is available only for:

• Strict liability offences;
• Certain Commonwealth offences under statutory provisions.

It is not available for:

• Absolute liability offences;
• Offences requiring proof of mens rea (because intent is already an element).

Courts determine whether an offence is strict or absolute liability by examining:

• The wording of the statute;
• The seriousness of the penalty;
• The purpose of the legislation;
• The level of moral culpability involved.

Key Legal Principles Summarised

The defence requires:

• A positive, affirmative belief;
• Actual consideration of the relevant fact;
• A belief that is both subjectively honest and objectively reasonable;
• A mistake relating to fact, not law.

The defence of honest and reasonable mistake of fact provides an important safeguard in strict liability offences. It recognises that while Parliament may remove the requirement to prove intention, it does not automatically criminalise those who act under a genuine and reasonable misunderstanding of factual circumstances.

However, the threshold is not low. Courts carefully scrutinise whether the accused genuinely turned their mind to the relevant fact and whether their belief was objectively justified.

If you are facing a strict liability charge in Victoria, careful legal analysis is essential to determine whether this defence can properly be raised.

For more information, read our blog article on the defence of honest and reasonable mistake of fact.