Helmut Reinmüller was a police officer in Vienna and at the Austrian Federal Criminal Police Office for 44 years, including 24 years as chief detective. 1992 he was the clerk of the criminal case The Grave Robbery of Mary Vetsera and published a non-fiction book about it in 2019 interested in the actual drama of the death of Crown Prince Rudolf and Mary Vetsera in the Mayerling hunting lodge in 1889 and worked on the case again as a cold case with its criminalistic perspective. Only documents that are still available today served as the basis for his research. Reinmüller is now presenting the results of his investigation in his book. Important people who were involved in the case are introduced and the facts are presented chronologically day by day. Describing important places, showing time-path diagrams, reconstructing important events and processes and underlining them with numerous illustrations. Finally, the author goes into the situation of Mary's mother, Baroness Helene Vetsera, who fell into the greatest disfavor, suffered numerous strokes of fate and was completely impoverished in Vienna when she died. Reinmüller even describes her as the third victim of the Mayerling drama. In his book, Reinmüller presents details that were previously unknown and have never been published. Hardback edition, in German, 250 pages with many illustrations.