Emmerson Wain Manning

Emmerson Wain Manning is known for Practical Instruction for Detectives: A Complete Course in Secret Service Study, a guide to detective work published by F. J. Drake in 1921, with evidence that the work was first copyrighted in 1916.

In the book’s preface, Manning says he had been connected for many years with two of the country’s largest private detective agencies, serving both as an operator and as an official. The book presents itself as a practical training manual, covering surveillance, investigation methods, and the everyday skills expected of detectives at the time.

Very little reliable biographical information about Manning appears to be widely available online beyond his authorship of this book. Because of that, he remains a somewhat shadowy figure today, remembered mainly through a concise, experience-based manual that preserves the tone and techniques of early modern detective work.