On 21 April 2010, the Russian Supreme Court ordered the Moscow City Court to hear an appeal in an ongoing Katyn legal case. A civil rights group, Memorial, said the ruling could lead to a court decision to open up secret documents providing details about the killings of thousands of Polish officers. On 8 May 2010, Russia handed over to Poland 67 volumes from "criminal case No. 159", launched in the 1990s to investigate the Soviet-era mass killings of Polish officers. Copies of these volumes, each comprising about 250 pages, were packed in six boxes. With each box weighing approximately , the total weight of all the documents stood at about . Russian President Dmitry Medvedev handed one of the volumes to the acting Polish president, Bronislaw Komorowski. Medvedev and Komorowski agreed the two states should continue to try to reveal the truth about the tragedy. The Russian president reiterated Russia would continue to declassify documents on the Katyn massacre. The acting Polish president said Russia's move might lay a good foundation for improving bilateral relations. In November 2010, the Russian State Duma admitted in an official declaration that Joseph Stalin and Soviet officials ordered the Soviet NKVD secret police under Lavrentiy Beria to commit the massacres.