A dual Russian-American citizen, Karelina was sentenced to 12 years in prison last August after a Russian court found her guilty of treason for donating just over $50 to a New York-based charity supporting Ukraine.
Hubbard, who turns 73 on Thursday, was sentenced to six years and 10 months in prison in October after being convicted in a closed court in Moscow of serving as a mercenary for Ukraine.
Gordon Black during sentencing in court in Vladivostok, Russia] Her lawyer has said she pleaded guilty in the hope of getting a lighter sentence, and that he would work towards securing her release in a future prisoner exchange.
Schneider was sentenced to six years in prison in September by a court in the Kaliningrad region for kidnapping his own son, after he tried to leave Russia with the four-year-old without permission from the boy's mother.
An ex-Marine, he was found guilty by a Russian court of assaulting a prison officer and a state investigator at a penal colony in Voronezh, south of the Russian capital.
