Brazil denies US extradition request for alleged Russian spy, approves extradition to Russia

Brazil has denied the US request to extradite alleged Russian spy Sergey Cherkasov.
Cherkasov was charged by the US with acting as an illegal Russian agent while in graduate school.
Brazil had already approved Russia's request to extradite Cherkasov on drug charges.
Cherkasov will remain imprisoned in Brazil until he completes his sentence for forgery.
The US hoped to use Cherkasov in a prisoner swap with Russia for detained Americans.