Five men went on trial at a military court in Moscow on Monday for the murder of Russian opposition leader Boris Nemtsov, who was gunned down outside the Kremlin last year.
The alleged triggerman, Zaur Dadayev, was a soldier in southern Russia's predominantly Muslim region of Chechnya when the crime was committed, the Interfax news agency reported.
The other defendents, brothers Anzor and Shadid Gubashev, Temirlan Eskerkhanov and Khamzat Bakhayev, face various charges ranging from illegally supplying a firearm to participating in a contract killing by an organized group.
Dadayev reportedly confessed early in the investigation to killing Nemtsov for insulting Islam and Chechnya's leader, Ramzan Kadyrov, but later recanted his confession.
Nemtsov's murder, in February 2015, occurred days before he was expected to lead a major opposition march and release a controversial report implicating the Russian military in the Ukraine conflict.