The next trial in March, 1938, involved twenty-one leading members of the party. This included Nickolai Bukharin, Alexei Rykov, Genrikh Yagoda, Nikolai Krestinsky and Christian Rakovsky. They were accused of being involved with Leon Trotsky in a plot against Joseph Stalin and with spying for foreign powers. They were all found guilty and were either executed or died in labour camps.
Stalin now decided to purge the Red Army. Some historians believe that Stalin was telling the truth when he claimed that he had evidence that the army was planning a military coup at this time. Leopold Trepper, head of the Soviet spy ring in Germany, believed that the evidence was planted by a double agent who worked for both Stalin and Hitler. Trepper's theory is that the "chiefs of Nazi counter-espionage" led by Reinhard Heydrich, took "advantage of the paranoia raging in the Soviet Union," by supplying information that led to Stalin executing his top military leaders.
In June, 1937, Mikhail Tukhachevsky and seven other top Red Army commanders were charged with conspiracy with Germany. All eight were convicted and executed. All told, 30,000 members of the armed forces were executed. This included fifty per cent of all army officers.
The last stage of the terror was the purging of the NKVD. Stalin wanted to make sure that those who knew too much about the purges would also be killed. Stalin announced to the country that "fascist elements" had taken over the security forces which had resulted in innocent people being executed. He appointed Lavrenti Beria as the new head of the Secret Police and he was instructed to find out who was responsible. After his investigations, Beria arranged the executions of all the senior figures in the organization.