** FILE ** Alexander Litvinenko, former KGB spy and author of the book "Blowing Up Russia: Terror From Within", is seen photographed at his home in London in this Friday, May 10, 2002 file photo. Russia's top prosecutor tells his British counterpart that Russia could prosecute the chief suspect in the Alexander Litvinenko killing if Britain presents sufficient evidence, the Interfax news agency reported. (AP Photo/Alistair Fuller)