John William Nixon

[1] Born and raised in Graddum, a townland located between the village of Kilnaleck and the hamlet of Crosskeys in County Cavan, Nixon became a district inspector in the RIC, and transferred to its successor in the then newly created region of Northern Ireland, the Royal Ulster Constabulary (RUC).

By 1922, he was responsible for controlling access to the Roman Catholic Ardoyne and "Bone" areas of Belfast, and worked closely with the Ulster Special Constabulary (USC).

Irish nationalist writer and activist Michael Farrell has alleged that during this period he led the Cromwell Club, an unofficial organisation of security officials responsible for killing several Catholic civilians.

[2] These allegations have not been independently confirmed and during his lifetime Nixon successfully sued The Derry Journal and a book publisher for libel.

This contravened RUC regulations, and he was dismissed on the orders of Sir James Craig, the first Prime Minister of Northern Ireland.