Now that Scotland Yard have handed their files on the Litvinenko investigation over to the Crown Prosecution Service, the BBC are hazarding a guess at who done it - former KGB officer Andrei Lugovoi in the Mayfair hotel with the radioactive teapot.
Mr Lugovoi met Mr Litvinenko on the day he fell ill, and radioactive polonium-210 has been found in a string of places he had visited in London. But Mr Lugovoi has said he is a witness and a victim but not a suspect... The BBC's Frank Gardner said police sources privately believed that the "finger of suspicion" pointed "clearly" at Mr Lugovoi.
Who ordered the killing is still unknown, but one thing for sure is that these babies won't be talking.
Wikipedia has a very thorough roundup of the Alexander Litvinenko poisoning so far. As always it's worth reading the Discussion section as you get interesting insights into the inner workings of Wikipedia:
Could somebody competent to do so please fix the picture? Some clever harry has posted Le Chiffre from Casino Royale, the new James Bond film. Yet Le Chiffre was only a user of benzedrine, not polonium!