MOSCOW – A Moscow jury acquitted three men charged in the killing of journalist and Kremlin critic Anna Politkovskaya. The verdicts were an embarrassing defeat for prosecutors in a trial compromised from the start by the absence of the suspected gunman and any alleged mastermind. Politkovskaya’s probes into atrocities in Chechnya and abuses by Russian authorities angered the Kremlin. Her killing underscored the risks run by journalists and government critics in Russia.