Defences to Criminal Charges

Criminal defences fall into two broad categories:

• Legal defences, which justify or excuse the conduct alleged;
  

• Factual defences, which dispute whether the offence actually occurred as alleged (e.g., alibi or mistaken identity). 
  

Understanding these defences is critical for anyone facing criminal charges and seeking the best possible outcome. 

What Is a Criminal Defence?

A criminal defence is a legal argument or evidence presented on behalf of an accused person to show that:

• The prosecution has failed to prove one or more elements of the offence; or
  

• There is a valid reason why the person should not be found guilty, even if the conduct occurred. 
  

If a defence is accepted, it can result in:

• An acquittal (not guilty verdict) where charges are dismissed;
  

• A reduction of charges through partial defences; or
  

• Mitigated sentencing in cases where responsibility is reduced. 
  

Common Criminal Law Defences in NSW

Here are key defences frequently raised in New South Wales criminal proceedings:

1. Self-Defence

Self-defence is a statutory defence that can apply where a person reasonably believes their actions were necessary to protect themselves or another from unlawful harm. If established, it can fully absolve the accused of criminal responsibility. 

2. Duress

Duress applies when an individual commits an offence because they were coerced by threats of serious harm or death. This is a complete defence, meaning it can lead to a not-guilty outcome if the threat would overpower an ordinary person. 

3. Automatism

Automatism involves involuntary conduct — for example, where a person’s actions were not under conscious control due to a medical condition or other impairment. If proven, the defendant may escape criminal liability because there was no voluntary conduct. 

4. Honest and Reasonable Mistake of Fact

This defence arises when a person genuinely and reasonably misunderstood a fact that negates an element of the offence. It applies mainly to strict liability offences, where intent is not required. 

5. Claim of Right

In property-related offences (like theft or robbery), a claim of right may apply if the accused honestly believed they were entitled to the property in question. This can result in acquittal if the belief was genuinely held, even if it was mistaken. 

6. Intoxication

Intoxication is not a complete defence in most cases but can be relevant where the offence involves a specific intent. Evidence of intoxication can impact whether the required intent was present. 

7. Mental Illness and Substantial Impairment

Where a person has a significant mental health impairment at the time of the offence, they may be legally incapable of forming criminal intent. This defence can lead to special orders focusing on treatment rather than punishment. 

8. Necessity

Necessity can apply where the accused committed the offence to avoid a greater harm — for example, acting under urgent and unavoidable circumstances. 

Complete vs Partial Defences

Some defences are complete, meaning they can result in acquittal (e.g., self-defence or duress), while partial defences may reduce the severity of the charge (such as extreme provocation reducing murder to manslaughter). 

Why Legal Advice Matters

Criminal defences are complex and highly technical. Choosing and successfully arguing the right defence requires detailed legal knowledge, a deep understanding of evidence, and strategic court advocacy. With strong legal representation, it is possible to:

• Identify all available defences based on the facts;
  

• There is a valid reason why the person should not be found guilty, even if the conduct occurred. 
  

• Gather supporting evidence such as expert reports, witness testimony, or records;
  

• Persuasively present defences in court to achieve acquittal or reduced charges;
  

• Protect your rights and future prospects.