The Amateur Crime

Anthony Berkeley Cox (July 5, 1893 - 1971) was a British crime fiction author, born in Watford, England. He was educated at University College, London, and married Helen Macgregor in 1932. He served in the British Army during World War I. Berkeley wrote under several names, including gloomy 'psychological' thrillers under the name of Francis Iles. Other pseudonyms included 'Monmouth Platts'. 

Berkeley was quite prominent amongst crime writers of his time and was associated with others in this field, including Christie, Sayers and Chesterton, in founding the Detection Club. The mysteries written as 'Anthony Berkeley' are more or less straight detective fiction, featuring one of two detectives: Roger Sheringham, an egotist whom Berkeley deliberately made as unpleasant as he could, and a dithery but much nicer elderly man, Mr. Chitterwick. Berkeley's The Poisoned Chocolates Case is a tour-de-force of Golden Age detection, with no fewer than six separate solutions proposed and argued for before the final conclusion is reached.