Top Storey Murder

From mysteryfile dot com: " Novelist and part-time criminologist Roger Sheringham follows along, as Scotland Yard puts together a case against a burglar who added murder to his last job. These were the leisurely days when the professional criminals were all known and readily identifiable by their characteristic methods of operation.

But Roger finds flaws in their· theories and strikes off on his own investigations, which increasingly point to an inside job. He also adds a secretary — the murdered woman’s niece — who mysteriously disclaims her rightful inheritance, and whom Roger finds secretly provoking in other ways as well."