awful realization that he had been the victim of a political assassination by agents of the russian state. >> an expert witness testified the polonium that killed litvinenko could only have come from russia. president putin's spokesman declined our request for an interview, and in march 2015, putin gave lugovoi a medal, the order of merit to the fatherland, second class, for his work in the douma. >> you think russia will ever come clean and this will be known? >> i believed one day we will know this. it will be very obvious for people to decide. >> in the years she's been looking for answers, other questions have multiplied, other deaths have been recorded. there was boris berezovsky, the russian oligarch litvinenko says he refused to assassinate, another prominent critic of putin. in 2013, he bad found dead in