Original: He has also been accused by Russian authorities of being involved in the murders of several leading critics of the Putin's regime, including Litvinenko and journalist Anna Politkovskaya, in an attempt to destabilize the country and discredit Putin.
Simplified: The Russian authorities have accused him of trying to murder several leading critics of Putin's regime, including Alexander Litvinenko and journalist Anna Politkovskaya, in order to make Putin look bad.