Homicide is the killing of one human being by another. Homicide is a general term and may refer to a noncriminal act as well as the criminal act of murder. Some homicides are considered justifiable, such as the killing of a person to prevent the commission of a serious felony or to aid a representative of the law. Other homicides are said to be excusable, as when a person kills in self-defense. A homicide can turn to different direction- Criminal homicide or non-criminal homicide, based on the intention, Actus reus and Mens rea of the defendant. A criminal homicide is one that is not regarded by the applicable criminal code as justifiable or excusable. All legal systems make important distinctions between different types of homicide, and punishments vary greatly according to the intent of the killer, the dangerousness of the killer’s conduct, and the circumstances of the act.

Murder: 
Murder is one type of homicide that is defined in the legal system as “Murder is the unlawful killing of human being with intention to kill or cause Grievous Bodily Harm (GBH).  Sir Edward Coke (Institutes of the Laws of England, 1797) defines “Murder is when a man of sound memory, and of the age of discretion, unlawfully killing within any country of the realm any reasonable creature in rerum natura under the King’s peace, with malice aforethought, either expressed by the party or implied by law, so as the party wounded, or hurt, etc. die of the wound or hurt, etc. within a year and a day after the same.”

Actus Reus of Murder: 
The actus reus of murder is unlawful killing of human being under the King’s peace. 
-    Unlawful Killing: The killing must be unlawful. Certain defenses, e.g. self-defense, will make a killing lawful. 
-    Person in being: The killing must be of a living human being, not dead or fetus. Killing baby in a mother’s womb will not be considered as murder, rather the defendant will be charged under section 20 of Offences against the Person Act 1861 for Grievous Bodily Harm. 
-    Under the King’s peace: Under the King’s / Queen’s peace means that the killing of an enemy in the course of war will not be murder.

Causation: 
The act (or omission) of the defendant must have been the legal cause of the death of the victim. Causation must be established.

Mens Rea of Murder: 
The Mens rea of murder is to have intention to kill or cause Grievous Bodily Harm (GBH) with Malice afore thought. The House of Lords in R v Moloney [1985] held that nothing less than intention to kill or cause grievous bodily harm (GBH) would constitute malice aforethought: merely foreseeing the victim’s death as probable was insufficient. Whilst the actus reas elements are normally easy to establish, there has been much debate over the mens rea elements – specifically the meaning of intention.  On occasions where a defendant argues that killing or causing GBH was not his main intention and he therefore does not fulfil the mens rea requirements for murder, the courts must consider the surrounding case law concerning indirect or oblique intention.

a)    Intention to Kill: 
Murder is a crime of specific intent. Intention in this context includes direct or oblique intent. Direct intent covers the situation where the defendant desired the death. Oblique intent covers the situation where the death is foreseen by the defendant as virtually certain, although not desired for its own sake. The most recent authority on intention is: R v Woollin (1998). It has been said that the direction in Woollin does not provide a definition of intention and the law still remains slightly unclear. In Matthews and Elleyne, Rix LJ stated, ‘we do not regard Woollin as yet reaching or laying down a substantive rule of law’. The ruling has also been criticised by Kaveny, who believes the difficulties in establishing a defendant’s foresight means that the jury should instead be focusing on the defendant’s purpose when carrying out the action.

b)    Intention to cause Grievous Bodily Harm (GBH):
In R v Vickers [1957], the Court of Appeal held that a defendant could be convicted of murder if it was established that he had intended to kill, or had intended grievous bodily harm. The latter was accepted as sufficient mens rea for murder because if a defendant was willing to inflict (GBH), how was he to know that the victim might not die? An intention to cause (GBH) at least evidenced a willingness to accept a substantial risk that the victim might die.

Punishment of Murder:
The punishment for murder, a mandatory sentence of life imprisonment, is fixed by the Murder (Abolition of Death Penalty Act 1965). On sentencing a murderer the judge may recommend to the Home Secretary the minimum period which should elapse before the prisoner is released on license.

HOMICIDE is the slaying of one human being by another. There are four kinds of homicide: felonious, excusable, justifiable, and praiseworthy, but it makes no great difference to the person slain whether he fell by one kind or another -- the classification is for the advantage of the lawyers.

Ambrose Bierce, The Unabridged Devil's Dictionary