There are three ways in which murder can be committed:
The accused can cause the victim’s death while intending to kill or cause really serious injury, or being reckless as to that result; 
The accused can unintentionally cause the victim’s death in the course or furtherance of certain violent crimes; and
The accused can unintentionally cause the victim’s death in order to escape arrest.
This topic addresses the first category of murder outlined above. See Constructive Murder (Topic Not Yet Complete) for information concerning the second and third categories.
Overview of Elements
Murder is a crime at common law. It has the following four elements, each of which the prosecution must prove beyond reasonable doubt:
The accused committed acts which caused the victim’s death;
The accused committed those acts voluntarily; 
The accused committed those acts while:
intending to kill someone or cause them really serious injury; or
[if reckless murder has been left to the jury] knowing that it was probable that death or really serious injury would result.
The accused did not have a lawful justification or excuse for those acts (such as self-defence, provocation, duress or sudden or extraordinary emergency).
Each of these elements is addressed in turn below.
Acts which Caused the Victim’s Death
The first element that the prosecution must prove is that the accused committed acts which caused the victim’s death. There are three aspects to this element:
The accused must have committed the relevant acts;
Those acts must have caused someone to die; and
The victim must have been a human being.
Accused must have Committed the Relevant Acts
For the accused to be found guilty of murder, the prosecution must prove, beyond reasonable doubt, that s/he committed the act or acts which are alleged to have caused the victim’s death.
In most cases it will be clear which act or acts were the cause of death, and so little time will need to be spent addressing this issue (other than directing the jury that before they can convict the accused, they must be satisfied that s/he committed the relevant act or acts) (Ryan v R (1967) 121 CLR 205).
Specific directions may be required where the death may have been caused by one or more acts in a series of acts. See Causation.
Where additional directions are appropriate, the jury should be directed about the different ways the causal act can be identified, and instructed that it is for them to determine:
What acts caused the victim’s death (see below); and
Whether the accused committed the relevant act or acts (Ryan v R (1967) 121 CLR 205).
Acts That Caused Someone to Die
The accused’s acts must have caused the victim’s death. That is, his/her acts must have "contributed significantly" to the death, or been a "substantial and operating cause" of it (Royall v R (1991) 172 CLR 378; R v Rudebeck  VSCA 155).
The acts must be such that an ordinary person would hold them, as a matter of common sense, to be a cause of the death. The mere fact that the accused’s conduct contributed causally to the death, or was a necessary cause of it, is not sufficient (Royall v R (1991) 172 CLR 378).
The accused’s acts do not need to be the sole cause of the death. A person can be criminally liable for a death that has multiple causes, even if he or she is not responsible for all of those causes (Royall v R (1991) 172 CLR 378).
Previously, the law held that a delay of more than "a year and a day" between the accused’s acts and the victim’s death meant that the accused’s acts could not be regarded as a cause of that death. That limitation has been abolished (Crimes Act 1958 s9AA), and now applies only to offences alleged to have been committed before 19 November 1991.
In many cases it will be unnecessary for the judge to do more than simply identify causation as an element of the offence. However, more detailed directions should be given if:
Causation was a live issue in the trial; or
An undirected jury might consider causation to be a live issue.
The cases where causation will be a live issue will include those where:
There were multiple possible causes of the death;
The death was delayed;
There were intervening acts between the accused’s actions and the victim’s death; or
The accused is alleged to have caused the death indirectly (Royall v R (1991) 172 CLR 378).
Causation is a question of fact for the jury and, where it is in issue, it is for the jury to determine what act or acts caused death. The judge must not impermissibly confine the jury’s role in determining the act which caused death (Koani v R  HCA 42 at ).
See Causation for further information about this issue.
Victim a Human Being
The accused must have caused the death of a "human being" (R v Hutty  VLR 338).
"Death" is defined to mean the irreversible cessation of circulation of blood in the body, or the irreversible cessation of all function of the brain (Human Tissue Act 1982 s41).
An unborn child is not classified as a "human being" for the purposes of murder and manslaughter (R v Hutty  VLR 338).
A child is treated as being "born" (and thus a "human being") when "he or she is fully born in a living state". This occurs when the child is "completely delivered from the body of its mother and it has a separate and independent existence in the sense that it does not derive its power of living from its mother" (R v Hutty  VLR 338).
Any evidence of independent existence will be sufficient for a child to be classified as a "human being" for the purposes of the law (R v Iby (2005) 63 NSWLR 278).
The mere fact that a child is still attached by the umbilical cord does not mean it is to be regarded as unborn (R v Hutty  VLR 338).
While killing an unborn child will not be murder or manslaughter, it may be child destruction (Crimes Act 1958 s10).
The second element that the prosecution must prove is that the acts which caused the death were voluntary (Ryan v R (1967) 121 CLR 205).
The issue of "voluntariness" concerns, at least, the accused’s conscious control of his or her bodily movements (He Kaw Teh v R (1985) 157 CLR 523).
The terms "deliberate" and "willed" are sometimes used to describe the voluntariness requirement (Ryan v R (1967) 121 CLR 205).
In murder trials it is orthodox to describe this element as requiring that the relevant acts be "conscious and voluntary", or "conscious, voluntary and deliberate". See R v Schaeffer (2005) 13 VR 337.
While a judge may use these terms to help explain the voluntariness requirement to the jury (R v Schaeffer (2005) 13 VR 337), they do not need to be used in every case. The use of such alternative terms, and the extent to which they need to be explored, will depend on the circumstances of the case.
If the term "conscious" is used care should be taken to ensure that it is not equated with voluntary action. The fact that an accused was conscious at the time of an act does not necessarily mean that act was committed voluntarily (see, e.g., R v Edwards  VSCA 92).
Knowledge of the circumstances that give an offence its criminal character is generally a component of intention, not volition. Thus an act remains voluntary even if it is performed in ignorance of fundamental facts that will determine culpability (R v O’Connor (1979) 146 CLR 64).
While the jury should always be directed to consider this element, where voluntariness is not in issue it need not be examined in detail (Ryan v R (1967) 121 CLR 205).
Terms such as "accidental", "unintentional", "involuntary" and "unwilled" all possess a degree of ambiguity. They can be used to signify either that:
The accused acts were not voluntary (addressing the second element); or
That the accused lacked the requisite intention to commit the crime (addressing the third element) (Ryan v R (1967) 121 CLR 205).
If such terms are used by counsel, the judge should take care to ascertain precisely which element is being addressed, and charge the jury accordingly.
Mental States: Intention and Recklessness
The third element that the prosecution must prove is that when the accused committed the acts that caused the victim’s death, s/he either:
Intended to kill someone or cause them really serious injury ("intentional murder"); or
Knew that it was probable that death or really serious injury would result from those acts ("reckless murder") (R v Crabbe (1985) 156 CLR 464).
The accused does not need to have intended to kill or injure the person who actually died, or to have been reckless about killing or injuring that particular person. It is sufficient if they had the necessary level of intention or recklessness in respect of some person, whether or not that was the person who was ultimately killed (La Fontaine v R (1976) 136 CLR 62). 
It is not appropriate to direct a jury about reckless murder in every case. The jury should only be directed about "reckless murder" where the evidence can properly support a conclusion that the accused acted recklessly (Pemble v The Queen (1971) 124 CLR 107; R v Barrett (2007) 16 VR 240; Aiton v The Queen (1993) 68 A Crim R 578, 587-590). 
One of the risks that arise from leaving reckless murder to the jury is that the jury may inadvertently treat the mens rea requirement as involving an objective rather than subjective analysis. This risk is likely heightened when the case also raises issues of voluntariness, manslaughter or self-defence (Herodotou v The Queen  VSCA 253, -).
In the context of murder, to commit an act "recklessly" is to commit that act knowing that someone will probably die or suffer really serious injury (R v Crabbe (1985) 156 CLR 464).
The word "probable" means "likely to happen". It can be contrasted with something that is merely "possible" (R v Crabbe (1985)156 CLR 464).
To have acted recklessly, the accused must actually have known that death or really serious injury would probably result from his or her acts. It is not sufficient for that danger to have been obvious to the reasonable person, or to the members of the jury (Pemble v The Queen (1971) 124 CLR 107; R v TY (2006) 12 VR 557; R v Barrett (2007) 16 VR 240).
The jury may use the fact that a reasonable person would have appreciated the probability of death or really serious injury to infer that the accused had such an awareness (Pemble v The Queen (1971) 124 CLR 107).
However, where such reasoning is open the jury must be warned not to conclude that the accused foresaw the probability of death or really serious injury simply because a reasonable person would have appreciated that probability (Pemble v The Queen (1971) 124 CLR 107; R v TY (2006) 12 VR 557).
Use of the word "reckless" should be avoided when charging the jury in murder trials, as it is liable to be confusing (La Fontaine v R (1976) 136 CLR 62).
Similarly, the word "might" should not be used. Recklessness is not established when the accused knew that particular consequences "might occur". The accused must have known that those consequences "would probably occur" (R v Crabbe (1985)156 CLR 464; R v Campbell  2 VR 585).
"Probable" is not a mathematical term. The accused does not need to have mathematically weighed the probability of death or really serious injury occurring, and the jury should not attempt to translate the accused’s knowledge into terms of mathematical probability (Boughey v The Queen (1986) 161 CLR 10).
It will generally be sufficient if:
The jury is directed to consider whether the accused knew that death or really serious injury was the probable or likely consequence of his or her acts; and
Reference is made to the distinction between what is probable or likely on the one hand, and what is only possible on the other (R v Crabbe (1985) 156 CLR 464; Boughey v The Queen (1986) 161 CLR 10; R v Faure  2 VR 537).
If a jury is to be directed on both reckless murder and involuntary manslaughter (whether by unlawful and dangerous act or by criminal negligence), it is vital that the directions draw an appropriate contrast between the mental states required for the two offences (Pemble v The Queen (1971) 124 CLR 107; R v TY (2006) 12 VR 557). See Manslaughter by Unlawful and Dangerous Act for further information.
Where recklessness is to be found by inference, the trial judge must identify the relevant evidence, and the inferences which can legitimately be drawn from that evidence (Pemble v The Queen (1971) 124 CLR 107; R v TY (2006) 12 VR 557).
The jury should be directed that the accused's circumstances are relevant to their determination of his or her state of mind. These circumstances may include age, educational and social background, emotional state and state of sobriety (Pemble v The Queen (1971) 124 CLR 107; R v Barrett (2007) 16 VR 240).
Really serious injury
For the third element to be satisfied, the accused does not need to have intended that someone die, or known that death would probably result from their actions. It is sufficient if s/he intended to cause someone serious non-fatal harm, or knew that such harm would probably result.
In Victoria, the degree of harm that must be intended is "really serious injury".
The phrase "really serious" should be used to properly indicate the gravity of the required intent (Wilson v R (1992) 174 CLR 313; R v Perks (1986) 41 SASR 335; R v Schaeffer (2005) 13 VR 337; R v Barrett (2007) 16 VR 240).
It appears to be necessary that the "really serious injury" intended or risked should be a bodily injury. This includes unconsciousness (R v Rhodes (1984) 14 A Crim R 124), but may not include purely psychological injuries.
The meaning of "really serious injury" is a matter for the jury to determine. It is unwise to elaborate on its meaning. The law gives only very general assistance to juries in this regard. While some injuries are manifestly too slight and some injuries clearly sufficient to answer the legal test, there remains an infinite variety of situations in which a jury might reasonably take either view (R v Rhodes (1984) 14 A Crim R 124).
There is no requirement that the harm intended be a life-threatening harm (R v Cunningham  AC 566.)
Defences to murder
Conduct that would otherwise be murder can be excused or justified by a number of discrete defences, including self-defence, provocation (for homicides committed before 23 November 2005), intoxication, duress and sudden or extraordinary emergency. Each of these defences is examined in detail in Part 8: Victorian Defences.
In murder trials it is commonly necessary to direct juries about available alternative verdicts, such as manslaughter.  It may also be necessary to direct the jury about a number of different defences or excuses, such as self-defence and provocation. The interrelationship between these issues means that the order in which they are addressed can affect the clarity of the charge.
For offences alleged to have been committed prior to 23 November 2005,  it is recommended that judges approach these topics in the following order:
The elements of murder;
Self-defence (to murder);
Voluntary manslaughter (provocation);
The elements of involuntary manslaughter;
Self defence (to manslaughter).
For offences alleged to have been committed on or after 23 November 2005 and before 1 November 2014 , it is recommended that judges approach these topics in the following order:
The elements of murder;
Murder self-defence (s9AC);
Defensive homicide (s9AD);
The elements of manslaughter; and
Manslaughter self-defence (s9AE).
For offences alleged to have been committed on or after 1 November 2014, it is recommended that judges approach these topics in the following order:
The elements of murder;
Self-defence (to murder) (s322K);
The elements of manslaughter; and
Self-defence (to manslaughter) (s322K).
If the victim dies in Victoria, the matter may be tried in a Victorian court, regardless of whether or not the causal acts occurred in Victoria (Crimes Act 1958 s9).
 This type of murder will simply be referred to as "murder".
 Although this element is often said to require the accused’s acts to be "conscious and voluntary", consciousness is simply one aspect of the broader voluntariness requirement (see, e.g., Ryan v R (1967) 121 CLR 205). This issue is addressed in more detail below.
 This is known as the doctrine of "transferred malice".
 See R v Hegarty  VSC 111 for a detailed discussion about the types of situations in which a direction on reckless murder may be appropriate.
 See Alternative Verdicts for guidance concerning the requirement to leave alternative verdicts to the jury.
 On 23 November 2005 the Crimes (Homicide) Act 2005 came into effect, introducing two statutory self-defence provisions (Crimes Act 1958 ss9AC and 9AE) and a new offence of Defensive Homicide (s9AD), as well as abolishing provocation. See Statutory Self-Defence (Pre-1/11/14) and Defensive Homicide for further information.
 On 1 November 2014 the Crimes Amendment (Abolition of Defensive Homicide) Act 2014 came into effect, introducing a single statutory self-defence provision for all offences (Crimes Act 1958 s322K), and abolishing the previous statutory murder self-defence, manslaughter self-defence and the offence of Defensive Homicide. See Statutory Self-Defence (From 1/11/14) for further information.