Charles Felix

Charles Felix was the pen name of Charles Warren Adams (1833–1903), an English lawyer, journalist, and publisher who wrote what is widely considered the first detective novel in the English language. The Notting Hill Mystery was serialized in Once a Week magazine beginning in 1862 and published as a novel in 1865 with illustrations by George du Maurier, grandfather of Daphne.

Adams predated the techniques that would define detective fiction by sixty years, and then disappeared into obscurity. Nobody saw the first detective novel coming from a lawyer who published other people's books and campaigned for the rights of laboratory animals, but that's probably the point.