At the Museum of Russian History at the Holy Trinity Monastery in Jordanville, New York, materials from Sokolov's investigation into the murder of the last Russian emperor's family are kept.

This archive contains items seized by soldiers of Kolchak's army in the summer of 1918 and by members of the investigation commission. Among them are personal belongings of the royal family: bed linens, handkerchiefs, clothing (shirts, sweaters of Nicholas II's son and daughters), laundry hangers, the false teeth of Dr. Botkin, the tunic of the Tsarevich, flip calendars, fragments of the walls of the Ipatiev House, epaulettes, numerous icons, amulets, crosses, and lamps that were in the home church, as well as documents, drawings, and photographs.

The investigative case of Sokolov is of particular value. Many of these items have not yet been fully studied and have never been published. A significant portion was transferred by Grand Duchess Maria Konstantinovna and Grand Duchess Olga Alexandrovna from Canada.