I want to know the answer to the following question:
Who released the prisoners in the 1950s?
All the background I'm provided with is that "On July 25, 1987, 300 Crimean Tatars staged a noisy demonstration near the Kremlin Wall for several hours, calling for the right to return to their homeland, from which they were deported in 1944; police and soldiers merely looked on.". Is that enough to answer the question?