Homicide refers, in general legal practice, to the killing of one human being by another. It is an umbrella term covering both criminal and non‑criminal killings and is used consistently across England & Wales, Scotland, Northern Ireland and Ireland. In all these jurisdictions, homicide is not itself usually the name of the main offences charged; rather, it is a descriptive category encompassing offences such as murder and manslaughter (England & Wales, Northern Ireland, Ireland) and murder and culpable homicide (Scotland). These core offences are defined and developed through a mixture of statute and case law. Criminal homicide typically requires that the defendant’s conduct caused death and that the required mental element (e.g. intention to kill or cause serious harm, or an applicable form of recklessness or gross negligence) is proved. Defences such as self‑defence, diminished responsibility, loss of control or insanity may excuse or mitigate liability. Homicide investigations and prosecutions carry the highest level of procedural scrutiny, sentencing powers and public interest. The term “unlawful killing” is often used in coroner’s inquests and fatal accident inquiries when examining deaths potentially amounting to criminal homicide.