MOSCOW – In the early 1950s, a group of prominent, mostly Jewish doctors from Moscow was accused of plotting to assassinate Soviet leaders on orders from the West. The accused were fired from their jobs, arrested and tortured. But after Josef Stalin died in 1953, Lavrenty Beria — one of Stalin’s longest-serving secret police chiefs, who oversaw the People’s Commissariat for Internal Affairs (NKVD) in 1938–1945 and spent decades filling the Gulags — called off the investigation.