The circumstances of the death of nine-year-old Tsarevich Dimitri, the youngest son of Ivan the Terrible, on May 15, 1591, were investigated according to the rules of criminal proceedings of those years. The progress of the investigation and its results are reflected in the case that went down in history as the “Investigation case about the murder of Tsarevich Dimitry Ivanovich on Uglich,” which is brought to the reader’s attention. We hope that this is the only investigative case in the history of Russia of the 16th century that has survived to the present day, will allow the reader draw your own conclusion about the tragedy that occurred, the completeness of the investigation, as well as the reliability of the official version of the prince’s death.