Putin called him a patriot. But who is Vadim Krasikov, a Russian released in the mass prisoner swap? The Associated PressPutin hit man seen as Russia’s big prize in prison swap: ‘High-value asset’ Fox NewsGermany’s ‘Deal With The Devil’ In Russia Prisoner Swap Barron’sWho Is the Russian Assassin Freed as Part of a Sweeping Prisoner Swap? The New York TimesGermany plays key role in prisoner swap with Russian assassin release Reuters