Freeman Wills Crofts was born June 1, 1879, in Dublin, the son of a British army doctor who died during foreign service while his son was still a child. His widowed mother later married Archdeacon Harding of the Church of Ireland, and Crofts was reared in the Harding home. He attended Methodist and Campbell colleges in Belfast and, at seventeen, began his engineering studies under his uncle, Berkeley D. Wise, then chief engineer of the Belfast and Northern Counties Railway. In 1899, Crofts was appointed junior assistant engineer for the construction of an extension of the Donegal Railway. In 1900, he was named district engineer at Coleraine for the Belfast and Northern Counties Railway and, ten years later, chief assistant engineer at Belfast for the same line. In 1912, he married Mary Bellas Canning, daughter of the manager of a local bank.
During a long illness and recovery in 1919, Crofts began to write to amuse himself. The result was The Cask, published in London by Collins in 1920, a novel generally hailed as a masterpiece of pure detection. He continued to publish almost yearly until 1929, when another serious illness forced him to choose between engineering and writing. He elected to continue writing; after he resigned his position with the railway, he and Mary moved near London, where he lived most of the rest of his life. In 1939, he was elected to the Royal Society of Arts. He died April 11, 1957, at the age of seventy-seven. Crofts’s other interests included gardening, carpentry, and music, as both an organist and a conductor. These interests are reflected by the characters in his novels. The personal traits most obvious in the novels, and especially in Inspector French, are those of a mind trained in mathematics and engineering methodically applying perseverance and logic to solving a problem or a murder.