Perverting the course of justice in NSW.

What is perverting the course of justice?

The charge lives in section 319 of the Crimes Act 1900 (NSW). The words are short. A person who does any act, or makes any omission, intending in any way to pervert the course of justice, is liable to imprisonment for 14 years. The reach of the offence comes from how widely those words are read.

Section 312 of the Act tells you what perverting the course of justice means. It is obstructing, preventing, perverting, or defeating the course of justice or the administration of the law. In plain terms, it is any conduct meant to stop the justice system from working the way it should, whether that is a police investigation, a court case, or the enforcement of the law.

The offence is deliberately broad because the ways a person can interfere with justice are endless. Rather than list them, Parliament made the test one of intention. If the act was done with intent to pervert the course of justice, the label of the act does not matter.

What does the Crown have to prove?

There are two things, and the Crown must prove both beyond reasonable doubt. First, that the accused did an act, or made an omission, that had a tendency to pervert the course of justice. Second, that when they did it, they intended in some way to pervert the course of justice. The intention is the heart of the charge.

The leading authority is the High Court decision in R v Rogerson (1992) 174 CLR 268. The Court held that the course of justice is perverted where a person impairs the capacity of a court or a competent authority to do justice. That can happen through a police investigation as much as through a court hearing, because the investigation is part of the process by which people are brought before the court.

Two points from the case law catch people out. The Crown does not have to prove that justice was actually perverted. The offence is complete when the act is done with the intention, even if it failed and no one was misled. And there does not need to be a court case on foot. The High Court confirmed in The Queen v Beckett (2015) 256 CLR 305 that a charge under section 319 does not require any proceedings to be pending. An act done during a police investigation, before a single charge is laid, is enough if the intention is there.

What are examples of perverting the course of justice?

The charge is laid in a wide set of situations. The common ones we see include giving police a false account to cover for someone, making up an alibi, and getting a friend or family member to say they were the driver so a licence or a demerit problem lands on the wrong person. That last one, a false driver nomination, is charged more often than people expect.

Other examples are interfering with evidence, such as deleting messages, wiping a phone, or hiding an item police are looking for. Pressuring, bribing, or threatening a witness to change their account, withdraw a statement, or stay away from court is another. So is providing false documents, forging a record, or lying in a statutory declaration to defeat a fine or a claim. In each case the question is the same. Was the act done with intent to interfere with the course of justice?

What is the maximum penalty in NSW?

The maximum penalty under section 319 is 14 years imprisonment. It is a serious indictable offence, and it is strictly indictable, which means it cannot be finalised in the Local Court. It is committed to the District Court, where it is dealt with on a plea or at trial before a judge and, if the matter goes to trial, a jury.

There is no standard non-parole period fixed for the offence. The 14 year figure is a ceiling, and the sentence turns on the seriousness of the conduct. But the offence carries a weight out of step with how minor the underlying act can look, because of what it strikes at. A lie about who was driving is a small act with a large charge attached.

False statements and false accusations to police.

Not every false thing said to police is a section 319 charge. The Act has a ladder of related offences, and which one is used depends on the conduct and how serious it is.

False accusation. Section 314 covers making an accusation intending a person to be investigated for an offence, knowing that person is innocent. The maximum is 7 years. This is the charge for framing someone, or reporting a person for a crime you know they did not commit.

Public mischief. Section 547B covers knowingly making a false report that causes police to start or continue an investigation, for example a false report of a stolen car or a made up crime. It is a Local Court matter with a lower penalty, and it is the charge for a false report that wastes police time without targeting a particular innocent person.

Tampering with evidence. Section 317 covers suppressing, concealing, destroying, altering, or fabricating something knowing it may be required as evidence in a judicial proceeding, done with intent to mislead the court. The maximum is 10 years. Section 318 deals with making or using a false official document to pervert the course of justice, and carries 14 years.

What is the difference between perverting justice and hindering police?

People use the terms loosely, but they are different charges with different penalties. Perverting the course of justice under section 319 is the most serious. It targets an intention to defeat the justice system itself, and carries 14 years.

Hindering the investigation of a serious indictable offence is a narrower charge under section 315, aimed at conduct that gets in the way of police investigating a serious crime, with a maximum of 7 years. Obstructing or hindering a police officer in the execution of their duty is different again. That is a summary offence dealt with in the Local Court, and it covers the everyday interference of getting in an officer's way or refusing to move on. We deal with the police powers side of this in our note on assaulting and resisting police.

The choice between these charges matters a great deal, because the same event can be charged high or low. Part of the defence work is testing whether the conduct really fits section 319, or whether it belongs in one of the lesser offences.

Pressure on a witness in a domestic violence matter.

This offence comes up often in family and domestic matters, and it is worth setting out plainly. A complainant is entitled to tell police they do not wish to proceed. Wanting a matter dropped is not a crime. What crosses the line is pressure applied to a witness, with intent to interfere with the case.

A person who threatens, bribes, or leans on a complainant to withdraw a statement, to change their account, or to stay away from court can be charged with perverting the course of justice. This can happen even where the parties have reconciled and both want the matter to end. Contact made in breach of an apprehended violence order can make it worse, and it is a separate charge, which we cover in our note on contravening an AVO. The safe course, always, is to say nothing to a witness about their evidence and to let the lawyers deal with the case. Our note on witnesses and statements explains where the line falls.

What are the defences?

Intention is the usual battleground. The Crown must prove the accused intended to pervert the course of justice. Where the act was careless, foolish, or done for another reason, the fault element is missing. A person who gives a mistaken but honest account, or who deletes messages in the ordinary course without any thought of an investigation, does not have the intention the section requires.

The act itself can also be tested. The conduct must have a tendency to pervert the course of justice. Where it could not have affected any investigation or proceeding, the charge is open to challenge. Identity is a defence where the Crown cannot prove the accused was the person who did the act. Duress may be open where a person acted under a real threat. And the charge may be the wrong one, where the conduct fits a lesser offence, or fits nothing at all.

How do courts sentence it?

Sentencing for this offence is stern, and prior good character offers less protection than in most cases. Courts treat perverting the course of justice as an attack on the system that everyone relies on, so general deterrence and denunciation carry great weight. Full time custody is a real prospect even for a person with no record and a good reputation.

The best known example is Einfeld v R [2010] NSWCCA 87. A former Federal Court judge made a false statement that another person, who had in fact died years earlier, was driving his car when it was caught speeding. He was convicted of perverting the course of justice and perjury and sentenced to full time imprisonment. The case is a reminder that the size of the underlying dishonesty, a speeding fine, is not the measure. The measure is the damage to the administration of justice.

Within that stern range, the court weighs how sophisticated and sustained the conduct was, whether it drew others in, and whether it actually affected a case. The sentencing factors in section 21A of the Crimes (Sentencing Procedure) Act 1999 then apply, alongside the person's subjective case, which we explain in our note on section 21A. An early plea of guilty attracts a discount of up to 25 per cent, set out in our note on the plea discount. Where custody is on the table, an intensive correction order may allow a sentence to be served in the community, but it is not assumed for this offence.

What we do for a person charged.

The first work is on the charge itself. These matters often start with a police allegation that reads worse than the evidence supports. We test whether the act had any real tendency to pervert justice, and whether the Crown can prove the intention, which is where many of these cases are won or lost. We also test the charge choice, because the difference between section 319 and a lesser offence changes everything about where the matter ends up.

The evidence usually turns on what was said and done, so recordings, messages, call charge records, and any account given to police are the documents that matter. Where the evidence is strong, the work turns to the plea, to reducing the objective seriousness, and to building a subjective case that gives the court a reason to keep the person out of gaol. This is a charge worth defending properly, because a conviction carries a real risk of full time custody and lasts a lifetime. Our note on the first thirty days of a matter explains how the early stages run.

Frequently asked.

Is lying to police a crime in NSW?

It can be. A false story told to deflect an investigation, or a false accusation against an innocent person, can be charged as perverting the course of justice under section 319 of the Crimes Act 1900 (NSW), which carries up to 14 years. A less serious false report that sets police off on a needless investigation can be charged as public mischief under section 547B. Not every lie is a crime, but a lie meant to interfere with a police investigation or a court case can be.

Can you go to jail for perverting the course of justice?

Yes. It is a serious indictable offence with a maximum of 14 years. Courts treat it as an attack on the justice system itself, so general deterrence is given great weight, and full time custody is common even for a person of prior good character. A former Federal Court judge received a full time sentence for a false story about a speeding fine.

Does a court case have to be on foot already?

No. The High Court confirmed in The Queen v Beckett (2015) that a charge under section 319 does not require court proceedings to be pending. An act done before any charge is laid, such as concocting a false alibi or planting evidence during a police investigation, can be enough if it was intended to pervert the course of justice.

Is asking someone to drop a statement perverting the course of justice?

It can be, and this is a real risk in domestic violence matters. A complainant is free to tell police they do not want to proceed. But a person who pressures, bribes, or threatens a witness to withdraw a statement, or to stay away from court, can be charged with perverting the course of justice. The line turns on whether there was pressure applied with intent to interfere with the case.

What is public mischief in NSW?

Public mischief is the lesser offence under section 547B of the Crimes Act 1900 (NSW). It covers knowingly making a false report that causes police to start or continue an investigation, for example a false report of a stolen car or a made up crime. It is dealt with in the Local Court and carries a lower penalty than perverting the course of justice.

To speak to a criminal defence lawyer, call Aaron Kernaghan on 0421 717 019.

This article is written by Aaron Kernaghan, criminal defence lawyer at Good Legal Lawyers, as at 12 July 2026. It is commentary and reflects the personal opinion of the author only. It is not legal advice, it is not a substitute for advice on your own matter, and it does not purport to be accurate or complete. Any matter referred to may be before the court and any person charged is presumed innocent. For advice on a specific matter, contact Aaron Kernaghan on 0421 717 019 or contact the firm.

More criminal-law commentary by Aaron Kernaghan.

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