MOSCOW A Moscow court acquitted three men of involvement in the murder of Kremlin critic and journalist Anna Politkovskaya on Thursday, leaving Russia's most politically charged killing in years still unsolved.
The prosecution said it would appeal but the failure to secure a single conviction for the crime -- the most high-profile in a spate of reporters' killings -- raised questions about Russia's resolve to protect freedom of speech.
"This failure amounts to a human rights crisis," Miklos Haraszti, media freedom representative for the Organization for Security and Cooperation in Europe, a rights and security watchdog, told Reuters.
The United States said it "regretted" the murder was still unsolved and urged Russia to track down those responsible.
"We urge the Russians to try and find those who are responsible and bring them to justice as soon as possible," said State Department spokesman Gordon Duguid.
U.S. Secretary of State Hillary Clinton is expected to meet Russia's Foreign Minister Sergei Lavrov in Geneva on March 6 and Politkovskaya's death, as well as other human rights concerns, are likely to be raised by the top U.S. diplomat.
After a four-month trial, the jury forewoman said brothers Dzhabrail and Ibragim Makhmudov were not guilty of acting as accomplices in the murder and cleared former police officer Sergei Khadzhikurbanov of organizing the crime.
The three defendants hugged their relatives after the judge ordered them released from the cage in the courtroom where they had been held. Ibragim Makhmudov, from Russia's Muslim Chechnya region, shouted "Allahu Akbar" or "God is great."
Politkovskaya, a 48-year-old mother of two who published scathing exposes of official corruption and rights abuses, was shot dead outside her apartment on October 7, 2006, after returning home from the supermarket.
Politkovskaya's family and former colleagues accused prosecutors of bungling their investigation. The man prosecutors suspect of pulling the trigger is on the run and they have never identified the person they believe ordered her murder.
"We demand, we need the real murderer, and we will achieve this," Karina Moskalenko, a lawyer for Politkovskaya's family, told reporters outside the courtroom.
She said Thursday's verdict would help the investigation.
KREMLIN UNDER PRESSURE
"Any 'guilty' verdict could allow investigators to hide behind it and say the job is done," she said. "Now there is a clear need to make investigation effective, engage an investigation team, which could not be manipulated by anyone."
The Kremlin denied any involvement in Politkovskaya's murder and said it was an attempt to discredit Russia. Vladimir Putin, Russian president at the time of the murder and now prime minister, said Russia was committed to solving the crime.
The crime fueled accusations -- denied by the Kremlin -- that under Putin democratic freedoms were eroded and opposition journalists had to fear for their lives.
The New York-based Committee to Protect Journalists ranks Russia as the world's third most dangerous place for reporters, after Iraq and Algeria.
"No prosecution will be complete until the triggerman and mastermind are in the dock," it said in a statement.
"Delivering justice for the murder of Anna Politkovskaya will demonstrate that the Russian authorities have the political will to end the silencing of human rights defenders," a statement by Amnesty International said.
The Politkovskaya trial echoed the case of Paul Klebnikov, a U.S. journalist shot dead in Moscow in 2004. His suspected killers were acquitted and attempted retrials have been delayed because some of the defendants cannot be tracked down.
Former colleagues of Politkovskaya said before the verdict they would pursue their own investigation into her killing.
Lawyers for Politkovskaya's family complained during the trial that detectives had not questioned Ramzan Kadyrov, the pro-Kremlin leader of Chechnya.
Politkovskaya had accused Moscow's forces and their local allies of committing human rights abuses during a campaign to stamp out an insurgency. Kadyrov has repeatedly denied any involvement in Politkovskaya's murder.