Quote Originally Posted by JJ
"The widow of the murdered former KGB spy, Alexander Litvinenko, has written to Vladimir Putin challenging the Russian President to prove he had nothing to do with her husband’s death."

Read here

Could anyone explain to me how a person can prove his "nothing to do"?
have you actually read the article?
“I have never said that I knew you were personally responsible. I said that if you did not make every effort to assist the UK authorities in the discovery of the perpetrators of this terrible crime, I could only assume that you must have something to hide.”
which is true of course.