As a true Russian tyrant, Vlad Putin
Feels fondness for rulin' an' lootin';
He hides behind smiles,
Usin' KGB wiles
To assassinate foes without shootin'.
Polonium killed Litvinenko,
Delivered by serpentine foe;
In Moscow, still smiling,
Vlad Putin's beguiling
While re-staging Joe Stalin's show.
The contamination is strange. The polonium would be smuggled in a very small sealed container. The container would stop any radiation (alpha) and there is no reason for any polonium to escape the container.
It is almost like someone trying to paint a trail back to Moscow with polonium contamination. This does not pass the smell test.