Paul Whelan, a U.S. citizen who is also a citizen in the U.K., Ireland, and Canada, has been found guilty in Russia in a closed trial and sentenced to 16 years in prison for espionage. He had been arrested in Moscow in 2018 by the Russian Federal Security Service (FSB).

The verdict was read in a Moscow court on Monday as Whelan stood in the defendant’s cage holding a sign that read “Sham trial,” among other things.

The case against Whelan, a 50-year-old former U.S. Marine, has proven to be a contentious issue between Washington and Moscow, as secrecy has surrounded the case ever since Whelan’s initial arrest.

Shortly after his arrest, Russia’s FSB released in a statement that he had been detained while on a “spy mission.” They later produced evidence with a flash drive containing classified information that was seized from his hotel room.