MOSCOW, AP – The alleged killers of American journalist Paul Klebnikov went on trial behind closed doors in the Moscow City Court on Tuesday.

Klebnikov, the editor of Forbes magazine’s Russian edition, was gunned down outside the magazine’s Moscow offices in July 2004.

Three ethnic Chechens are standing trial in connection with the killing, and three others are wanted. Prosecutors say that Kazbek Dukuzov and Musa Vakhayev killed Klebnikov on orders from another Chechen, Khozh-Akhmed Nukhayev, who was the subject of a critical book by Klebnikov titled “Conversations with a Barbarian.” Nukhayev remains at large.

The alleged role of the third defendant, Fail Sadretdinov, is unclear. Sadretdinov, a notary, has been charged with attempted murder and organizing the criminal group alleged to have killed Klebnikov but prosecutors have drawn no direct connection between him and with the American’s murder, according to Russian media reports.

“Much will depend on how the evidence is presented,” Larisa Maslennikova, a lawyer representing Klebnikov’s family, was quoted as saying by the RIA-Novosti news agency.

The public was to have no access to the 12-person jury trial because, according to the court, some of the trial materials are secret.

The U.S.-based Committee to Protect Journalists assailed the decision to close the trial to the public.

“A transparent and credible prosecution is necessary not only to ensure justice in the Klebnikov case but to end the murderous cycle of violence against journalists in Russia,” committee executive director Ann Cooper said in a statement issued Monday.

Many observers have cast skepticism on the official account of the motives, suggesting that anger over Klebnikov’s work for Forbes was most likely the motive for the killing. They say the U.S journalist may have made enemies while investigating corruption and the still-murky post-Soviet business world.