… whereas in the US is always referred to as homicide.
No it isn’t and isn’t an American import.
The roots are in Latin and Germanic languages.
In classical Latin, homicida is a murderer - man who murders.
It’s partly a borrowing from French as well as Latin but also occurs in Spanish and Portuguese.
Homicide can be found in English writing as far back as the 14th century. It’s in Chaucer’s The Monk’s Tale and also in Shakespeare’s Henry Vi Part 1 - Salisbury is a desperate Homicide. Lord Byron - And her, the homicide and husband-killer.
However, from the 19th century that use became less common than its use to describe the act of killing.
The word murder is inherited from Germanic languages.
In law murder is “criminal homicide with malice aforethought” The deliberate and unlawful killing of a human being in a premeditated manner.
In earlier centuries was written as murther. Again in Shakespeare, Titis Andronicus. His traitorous sonnes, That dide by law for murther of our brother.
There are many, many example of both homicide and murther (and murder) in English writing long before anyone set sail for the New World.
The term murder can also be found in American writing. Pennsylvania Statutes: All murder which shall be perpetrated by..any kind of willful, deliberate, or premeditated killing, shall be deemed murder of the first degree; and all other kinds of murder shall be deemed murder in the second degree. Cecil Roberts, Adrift in America: The farmer lived for 48 hours; however he lived long enough to make it only murder in the second degree.
I’ve watched enough episodes of Law & Order USA and its spin offs to know that the legal charge is murder or manslaughter. Watch this clip as an example:
www.youtube.com/watch?v=T3hyu9He09U&list=PL9DxL1Q_FD-O3UcqT80VUGD_sr2H5WP1o&index=4
Whenever these discussions come up, I would urge people to use their library card and log into the online Oxford Engish Dictionary. It will dispel this notion that words arrive here from America. They will have been taken to America by settlors or been familiar there through writing. Before America gained its independence, most printed matter was exported from Britain.