Malice aforethought bedeutet den Vorsatz, der bewiesen werden muss, um den Angeklagten wegen Mord in England und Wales zu verurteilen. Es wird traditionell mit vorbedachte böse Absicht übersetzt. Der Begriff wird immer wieder von den Gerichten verfeinert. Er klingt einfacher, als er ist. Der Mord muss nicht geplant sein, es reicht, wenn in einer Messerstecherei einer in Augenblick des Zustoßens will, dass der Verletzte stirbt oder sehr schwer verletzt wird.

Malice aforethought is the form of mens rea (mental element required for conviction of most crimes) that makes a homicide murder in the common law. (Murder is still a common-law offence in England and Wales, whereas most criminal offences have been codified). The usual present possibilities of malice aforethought, roughly speaking (I’m not a legal scholar) are:

either
intending to kill, or
intending to cause grievous bodily harm, or
intending to do any act foreseeing death or grievous bodily harm as the natural and probable result (e.g. when driving away from the scene of a crime, knocking down and killing someone).

Of course, intention is a wide field (just like Vorsatz in German law).

Malice aforethought does not mean premeditated murder as the term is usually used, though, that is, not a planned murder. It’s sufficient if an attacker at the moment of attack wants the victim to die or to be very seriously injured. However, the term premeditated murder is sometimes used in this second sense too.

I see the topic was even mentioned in ‘The Professor and the Madman.
A Tale of Murder, Insanity, and the Making of The Oxford English Dictionary’ by Simon Winchester, which I haven’t read:

bq. The ‘malice aforethought’ which enters into the legal definition of murder, does not (as now interpreted) admit of any summary definition. A person may even be guilty of ‘wilful murder’ without intending the death of the victim, as when death results from an unlawful act which the doer knew to be likely to cause the death of some one, or from injuries inflicted to facilitate the commission of certain offences.

In what jurisdictions is the term still used? American states have statutory definitions of murder nowadays, but these often use the term malice aforethought. Here’s the federal definition of murder:

bq. Murder is the unlawful killing of a human being with malice aforethought. Every murder perpetrated by poison, lying in wait, or any other kind of willful, deliberate, malicious, and premeditated killing; or committed in the perpetration of, or attempt to perpetrate, any arson, escape, murder, kidnapping, treason, espionage, sabotage, aggravated sexual abuse or sexual abuse, burglary, or robbery; or perpetrated from a premeditated design unlawfully and maliciously to effect the death of any human being other than him who is killed, is murder in the first degree. Any other murder is murder in the second degree.

I have a Nolo Press book on criminal law that says first degree murder requires malice aforethought, but second-degree murder doesn’t. I don’t think that can be right – it’s manslaughter, voluntary or involuntary, that doesn’t require malice aforethought.

These unfinished ruminations relate to a post by Mark Liberman at Language Log.

That post is more concerned with the form of the words and whether the invented variant ‘malicious forethought’ is wrong or not. It quotes a number of dictionary definitions. Definitions from non-legal dictionaries always sound different from the pages and pages written on the term in criminal-law textbooks.

Incidentally, this closing remark:

bq. In the technical jargon recently invented for the purpose, the count of 2,990 Google hits for malicious forethought translates to 698 whG/bp (web hits on Google per billion pages), while malice aforethought’s 21,400 ghits is 4,994 whG/bp.

seems to have an unwarranted faith in Google’s ‘billion pages’. But perhaps there is an explanation for the huge numbers of hits you can never display.