Yesterday, news were published about Russia’s involvement in the murder. Alexander Litvinenko was in 2006 poisoned by polonium-210, a rare and highly radioactive isotope. This type of poisoning is very hard to detect, or even impossible if long time passes. Polonium-210 will decay to lead-206, while it emits alpha radiation. The remaining lead cannot be distinguished from lead from other sources. Polonium seems to be the perfect poison for those who can get hold of it, which is probably very difficult, except for assassins working for a government.
There is more to this story than the murder itself. In the book Death of a Dissident about Alexander Litvinenko, it is claimed that a Russian government agency was behind Russian apartment bombings. If that is true, it would be one of the many false flag operations, which governments have carried out.