Amnesty International designated Son a prisoner of conscience and described Son's espionage conviction as "a travesty of justice".
The American inquiry into the case has produced one espionage conviction and a guilty plea and is continuing, the Federal Bureau of Investigation said Friday.
That conflict of interest might run afoul of State Department rules, the investigator said, but would not suffice for an espionage conviction.
In 1942, he and 32 other members of the Duquesne Spy Ring were convicted in the largest espionage conviction in the history of the United States.
Over the last three years this country has seen 26 espionage convictions.
His is the first espionage conviction of a Westerner in Russia since the end of the cold war.
Life in prison is the maximum punishment for an espionage conviction.
I don't think we can get an espionage conviction from a single phone number.
What is new is the extent of this appalling activity - a record of 26 espionage convictions in the last three years.
Within a month the operation ended, resulting in espionage convictions for the agents.