British Government Blames Kremlin for Assassination
Putin is upset, of course. But the burden of solving this matter lies with him. If he cannot control his own intelligence agencies and the polonium-210 they have at their disposal then he should take control NOW.
On the other hand, if he DOES control the agency with an iron fist (and don't forget that he once headed the Russian intelligence) then he owes the British government a better response than to blame THEM for the problem!