Many of his novels were set in London, including a seven-book series featuring the fictional detective Chief Inspector Wake of Scotland Yard.

[3] His first book was an historical study of The Viceroys of Ireland, published by John Long in London in 1912, which he wrote as Charles O'Mahony.

He published seven novels featuring Chief Inspector Wake of Scotland Yard, starting with Murder in Piccadilly in 1936.

[14] In fiction, The Portland Place Mystery (1926) was described as working its way "smoothly along the accepted lines of high life romance.

"[15] Poison in Kensington (1934) features a blackmailing doctor of medicine whose motives are revealed to be pure in the end in a plot the reviewer found unlikely.

Nonetheless, Edwards identified in O'Mahony an affinity for the London underworld found in districts such as Soho, and a willingness for his characters to mention contemporary criminal cases such as the rape and murder of 10 year old Vera Page in 1931 which is referenced in the book by O'Mahony's detective Wake.