What Happens If You Defend Yourself With an Illegal Weapon in NSW?

At National Criminal Lawyers®, our clients often ask: “What if I only had the illegal weapon because I needed to protect myself?” It’s a fair question. On one hand, the law recognises your right to defend yourself or another. On the other, NSW has some of the strictest weapons laws in Australia, and possessing or using a prohibited weapon can itself be a serious crime.

So, what happens if you defend yourself with an illegal weapon in NSW? Can self-defence save you, or will you face criminal liability for the weapon regardless? This blog unpacks the law, looks at case examples, and explores the difficult balance between protection and prohibition.

The Right to Self-Defence in NSW

Under section 418 of the Crimes Act 1900 (NSW), self-defence is a complete defence to charges of assault, wounding, or even homicide. You are not criminally responsible if:

1. You believed your conduct was necessary to defend yourself (or another), and
   
2. Your conduct was a reasonable response in the circumstances as you perceived them.
   
3. If both limbs are satisfied, you must be found not guilty of the assault-related offence.

But here’s the catch: self-defence protects against the act of violence, not necessarily against possessing the weapon itself.

Illegal Weapons: What the Law Says

NSW regulates weapons under the Weapons Prohibition Act 1998 (NSW).

• Section 7 makes it an offence to possess or use a prohibited weapon without a permit.
• The maximum penalty is 14 years imprisonment if dealt with on indictment.

Examples of prohibited weapons in NSW include:

• Flick knives, daggers, and knuckle dusters.
• Taser devices, mace, and pepper spray (without lawful excuse).
• Crossbows, slingshots, and certain martial arts weapons.
• Firearms without a licence.

This means that even if you never intended to use the weapon unlawfully, merely having it can be an offence.

What If You Use an Illegal Weapon in Self-Defence?

If you use an illegal weapon in a genuine act of self-defence, two legal issues arise simultaneously:

1. The self-defence claim: Were your actions necessary and reasonable in the circumstances? If yes, you may be acquitted of the violence-related charge.
   
2. The weapons charge: Did you unlawfully possess or use a prohibited weapon? If yes, you may still face conviction and penalties, even if your use of the weapon was defensive.

In other words, self-defence may protect you from an assault charge, but not from the weapons offence.

Case Law: Self-Defence and Weapons

R v Katarzynski [2002] NSWSC 613

This case is regularly cited in NSW for how self-defence is assessed. The court confirmed that the jury must apply both the subjective test (what the accused believed) and the objective test (whether the response was reasonable). While not specifically about weapons, it establishes the framework courts use when considering force in defence.

Police v K [2009] NSWLC

A man used pepper spray to defend himself in a street fight. The court accepted that the threat was real but still convicted him of possessing a prohibited weapon, as he had no lawful authority to carry the spray.

These cases highlight that while the use of force might be excused, the weapon possession offence usually stands.

Charges You Could Face

Depending on the facts, defending yourself with an illegal weapon in NSW could expose you to:

• Weapons Prohibition Act 1998 (NSW) offences (possession, use).
  
• Crimes Act 1900 (NSW) offences (if self-defence fails, you could be charged with assault, wounding, or even manslaughter).
  
• Summary Offences Act 1988 (NSW) (offensive implement in a public place).

The overlap means you might beat the assault charge but still carry a criminal record for weapons possession.

Jurisdictional Discretion and Sentencing

NSW courts often face difficult balancing acts in these cases. Judges may show leniency in sentencing if:

• The weapon was genuinely used defensively.
• The threat to the accused was serious and immediate.
• The accused has no criminal record.

However, as the Judicial Commission of NSW Sentencing Bench Book notes, deterrence is also critical in weapons cases. Courts routinely emphasise that the law discourages arming oneself in advance.

Why Self-Defence and Weapons Don’t Mix Well

The policy reason behind these laws is clear: allowing people to carry and use weapons under the guise of “self-defence” would undermine public safety. NSW courts stress that:

• People are entitled to defend themselves, but
• They are not entitled to arm themselves unlawfully in anticipation of danger.

This distinction is why weapons possession charges usually stand, even if self-defence is accepted for the violent act.

National Criminal Lawyers®: Defending Weapons and Self-Defence Cases

At National Criminal Lawyers®, we regularly defend clients facing a mix of weapons charges and assault-related allegations. We know how to:

• Argue self-defence under s 418 Crimes Act to beat violence charges.
• Present strong mitigation on weapons charges to avoid prison, push for a s 10 dismissal, or secure a Conditional Release Order without conviction.
• Highlight context: Was the weapon improvised? Was the threat serious? Did the accused panic rather than plan?

Contact us

If you or someone you know has defended themselves with an illegal weapon in NSW, the consequences can be complex and serious. You may face multiple charges, with your liberty and record at risk.

📞 Call 1800 CRIM LAW today to speak with one of our expert weapons offence lawyers in Sydney. At National Criminal Lawyers®, we will fight to protect your rights, build the strongest possible defence, and work towards keeping your record clean.