From the collection: "Fifty Amazing Hairbreadth Escapes" (various authors) [1937].
"Ex-Detective-Inspector Wensley was, before his retirement, Chief Constable of the Criminal Investigation Department of Scotland Yard. One of the best-known cases on which he worked was the Siege of Sidney Street, and here he gives his first-hand account of a crime which stirred the whole country."
For a more candid approach see "Traitors Within" (1933) by Herbert Fitch (archive.org).