The grave of Alexander Litvinenko at Highgate Cemetery
Here is a British newspaper providing one perspective: http://www.theguardian.com/world/2016/jan/21/alexander-litvinenko-was-probably-murdered-on-personal-orders-of-putin
Here is pro-Kremlin Sputnik International providing another: http://sputniknews.com/europe/20160121/1033442767/litvinenko-public-inquiry-findings.html