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Section 23A Crimes Act 1900
Defence to Murder Substantial Impairment

Being charged with murder can be highly stressful and emotionally draining, however there are various ‘defences’ that you can raise to explain your actions and obtain a better outcome in your case.

One such defence is ‘substantial impairment of the mind,’ which is contained in section 23A of the Crimes Act. This defence only applies in murder cases.

‘Substantial impairment of the mind’ is what is known as a ‘partial defence,’ which means that if you raise it successfully, the charge of murder will be downgraded to manslaughter.

This means that you will face a maximum penalty of 25 years imprisonment as opposed to life imprisonment, which applies in murder cases.

Section 23A says that the defence will be raised if you prove you were suffering from a pre-existing ‘substantial impairment of the mind’ at the time of the offence that was so great that it affected your ability to understand events, judge whether your actions were right or wrong, or control yourself.

If you wish to raise the defence of ‘substantial impairment of the mind,’ you will have to prove that you suffered from an underlying mental condition. You can do this by providing evidence to the court, for example, psychiatric reports and assessments, to show how the mental condition affected you.

If you’ve been charged with murder and you’re wondering if the defence of ‘substantial impairment of the mind’ applies in your case, you should get advice as soon as possible from a highly experienced criminal defence lawyer.

At Sydney Criminal Lawyers®, we exclusively practice criminal law, with a particular specialty in murder cases.

Our specialist knowledge of this complex area of law, combined with our experience winning these types of cases means that our clients have a leading advantage when it comes to fighting their murder charges.

Our senior legal team is made up of Accredited Criminal Law Specialists who can advise you of any defences that you are able to raise, and will dedicate the time and effort to obtain all relevant evidence to support your case, such as mental health reports or assessments.

Our outstanding advocates can then give you the best possible representation in court by developing a compelling case and putting forth all evidence to ensure you get a positive result in your case.

If you want the best advice on how to raise a defence such as ‘substantial impairment of the mind’ in your murder case, call us today on (02) 9261 8881 and let our murder specialists help you.

The Legislation

Section 23A of the Crimes Act 1900 contains the defence to murder of ‘substantial impairment by abnormality of mind,’ which reads as follows:

23A Substantial impairment by abnormality of mind

(1) A person who would otherwise be guilty of murder is not to be convicted of murder if:
(a) at the time of the acts or omissions causing the death concerned, the person’s capacity to understand events, or to judge whether the person’s actions were right or wrong, or to control himself or herself, was substantially impaired by an abnormality of mind arising from an underlying condition, and
(b) the impairment was so substantial as to warrant liability for murder being reduced to manslaughter.

(2) For the purposes of subsection (1) (b), evidence of an opinion that an impairment was so substantial as to warrant liability for murder being reduced to manslaughter is not admissible.

(3) If a person was intoxicated at the time of the acts or omissions causing the death concerned, and the intoxication was self-induced intoxication (within the meaning of section 428A), the effects of that self-induced intoxication are to be disregarded for the purpose of determining whether the person is not liable to be convicted of murder by virtue of this section.

(4) The onus is on the person accused to prove that he or she is not liable to be convicted of murder by virtue of this section.

(5) A person who but for this section would be liable, whether as principal or accessory, to be convicted of murder is to be convicted of manslaughter instead.

(6) The fact that a person is not liable to be convicted of murder in respect of a death by virtue of this section does not affect the question of whether any other person is liable to be convicted of murder in respect of that death.

(7) If, on the trial of a person for murder, the person contends:
(a) that the person is entitled to be acquitted on the ground that the person was mentally ill at the time of the acts or omissions causing the death concerned, or
(b) that the person is not liable to be convicted of murder by virtue of this section,
evidence may be offered by the prosecution tending to prove the other of those contentions, and the Court may give directions as to the stage of the proceedings at which that evidence may be offered.

(8) In this section: “underlying condition” means a pre-existing mental or physiological condition, other than a condition of a transitory kind.

Why Choose Sydney Criminal Lawyers®?

Going to court can be nerve-racking, but having a strong and compassionate legal team behind you can make the experience significantly easier to deal with. Here are 12 reasons to choose our multi-award winning legal team:

  1. Proven Track Record of Exceptional Results

    Sydney Criminal Lawyers® consistently achieves outcomes which are in the highest percentile of the Judicial Commission’s sentencing statistics for criminal cases.

    Our legal team devises effective case-strategies and fights hard to have cases dropped entirely or charges downgraded – saving clients the time, expense and stress of a defended hearing or jury trial.

    Where cases nevertheless proceed, our lawyers have an outstanding track record of winning defended Local Court hearings, and complex jury trials in the District and Supreme Courts.

    We also consistently win appeals in the District and Supreme Courts (including the NSWCCA) after clients have received unsatisfactory results with other law firms in the lower courts.We are one of the few firms to achieve successful criminal law appeals in the High Court of Australia.

    Where our clients wish to plead guilty, we frequently achieve ‘dismissals’ and ‘non convictions’ in cases where other lawyers have advised there is no chance of doing so.

  2. Highest Level of Client Satisfaction

    We have the best and most comprehensive client review record of any law firm in Australia.

    Regular communication, accessibility and quality service are our team’s highest priorities.

    We are committed to thoroughly explaining all steps involved in the criminal law process, providing regular updates throughout the proceedings, and making ourselves accessible and responsive.

    We are passionate about providing an exceptional level of service to our clients, and we fight hard to achieve optimal results in the shortest period of time.

  3. Australia’s Most Awarded Criminal Law Firm

    We have received more awards and accolades than any other criminal law firm in Australia. Our team has been awarded “Criminal Defence Firm of the Year in Australia” in a number of prestigious and competitive awards programs for several years running.

    The awards recognise our exceptional track record of results, our outstanding client service, the high level of satisfaction we achieve, the affordability of our services and our overall excellence.

  4. Fixed Fees

    We want our clients to know exactly how much their cases will cost from the very start. That’s why we were the first criminal law firm in Australia to publish ‘fixed fees’, back in 2004.

    We offer fixed fees for most types of criminal cases and services.Our fixed fees apply to a range of Local Court cases such as drink driving, drug possession, fraud, common assault and AVOs, and also specific services such as prison visits, bail applications, appeals and defended hearings.

    Unlike many other law firms, our fixed fees are published on our website – which ensures transparency and certainty.

  5. Free First Appointment

    For those who are going to court, we offer a free first conference of up to an hour with one of our Senior Criminal Defence Lawyers.

    We also offer a free first conference to those who have received an unsatisfactory result after being represented in court by another law firm, or after representing themselves, and wish to appeal.

  6. Specialist Lawyer Guarantee

    We guarantee that only lawyers with substantial criminal defence experience will work on your case and appear for you in court.

    This ensures our clients receive the highest quality representation from an experienced, specialist criminal lawyer.

  7. All NSW Courts

    From Bombala to Broken Hill, our lawyers appear in courts throughout New South Wales – and across Australia for Commonwealth cases.

    And we offer fixed fees for most criminal and traffic law cases throughout the state.

  8. Accredited Specialists

    Our entire firm is exclusively dedicated to criminal law – which makes us true specialists.

    All of our lawyers have years of experience representing clients in criminal cases, and our principal has been certified by the Law Society of NSW as an Accredited Criminal Law Specialist since 2005.

    An ‘Accredited Specialist’ is a lawyer who has practised for at least 5 years in a particular field of law (such as criminal law), has passed a rigorous assessment process conducted by the Law Society of NSW, and has been selected by the Specialist Accreditation Committee of the Law Society as an expert in the field.

    Accredited Specialists are required to undertake more training each year than other lawyers and must be successful in having their accreditation renewed every year. Specialist Accreditation is the mark of a true specialist.

    Our firm’s specialist experience ensures you receive the best possible result, whatever your criminal law case may be.

  9. Results-Focused Law Firm

    Our team is passionate about achieving results, and unlike many other law firms, our lawyers do not have monthly financial ‘budgets’ to meet.

    The absence of budgets means our lawyers are entirely focused on achieving optimal results in the shortest space of time; whether by getting charges dropped or downgraded at an early stage or having cases ‘thrown out of court’.

    Not having budgets also means our lawyers are not under pressure to engage in unscrupulous practices such as unnecessarily adjourning cases or ‘overcharging’ clients – which, sadly, is a common complaint against many other lawyers and law firms.

    No budgets encourages regular consultation between lawyers within the firm – promoting an ‘open door’, team environment where lawyers bounce ideas off one another, formulate case strategy together and benefit from each other’s specialised experience, methods, techniques and insights.

    The result is a firm which delivers optimal outcomes in the shortest time periods, at the least expense and stress to our clients.

  10. Team of Lawyers Behind You

    Our clients benefit from the pool of knowledge that only an extensive team of experienced criminal defence lawyers can provide.

    Our lawyers regularly consult one another to stay ‘ahead of the pack’ in the ever-changing field of criminal law – constantly devising, refining and implementing specialised techniques which ensure our clients achieve the best possible outcomes.

    A team approach is particularly important when it comes to serious criminal cases such as murder, commercial drug cases, serious and sexual assaults, large-scale fraud, robbery and other ‘indictable’ cases.

    In such matters, clients reap the benefits of several lawyers devising and executing case strategies which maximise the chances of having cases dropped or downgraded at an early stage, or ‘thrown out of court’ – often saving clients a great deal of cost, time and anxiety.

  11. Familiar with Magistrates and Judges

    Each of our lawyers appears in court on a daily basis, and has done so for years. We have therefore been able to develop an understanding of, and rapport with, magistrates and judges in Sydney and indeed across the state.

    Our team’s extensive experience before the courts ensures your case is tailored to the specific nuances of individual judicial officers, maximising the likelihood of a favourable result.

  12. Convenience

    We have offices in locations across the Sydney Metropolitan Area and beyond, including:

    • the Sydney CBD, on Castlereagh Street, directly opposite Downing Centre Court,
    • Liverpool, directly opposite Liverpool Local Court, and
    • Parramatta, near the justice precinct.

    We offer free parking at our Sydney CBD and Liverpool locations, and all of our offices are close to train stations and bus terminals.

    For those who are unable to attend our offices, we offer conferences by telephone, Skye and FaceTime anywhere around the world.

    If you are going to court and wish to arrange a free first consultation, call our 24 hour hotline on (02) 9261 8881 or send us an email at info@sydneycriminallawyers.com.au.

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