The triggerman in the drive-by murder of Russian opposition leader Boris Nemtsov has been sentenced to 20 years in prison. The bold killing of Nemtsov, 55, on a bridge near the Kremlin shocked many Russians; questions remain about who reportedly placed a large bounty on his life.Prosecutors had sought a life sentence for Zaur Dadayev, a former officer in the security force of the Russian province of Chechnya, for killing Nemtsov in February of 2015. Instead, he was sentenced to 20 years. His four accomplices were handed sentences of 11 to 19 years. All five were also fined around $1,650. Their defense lawyers say they will appeal."The men were allegedly offered 15 million rubles ($240,000) to murder the politician," reports The Moscow Times, citing the same figure that has been reported elsewhere.An advocate of democratic reforms, Nemtsov was once seen as the political heir to Russia's former President Boris Yeltsin, under whom he served as a deputy prime minister in the 1990s."Nemtsov was a prominent critic of Russian President Vladimir Putin, accusing his government of corruption and fighting a covert war in Ukraine," NPR's Lucian Kim reports from Moscow. "A trail of clues led to Chechnya, which is ruled by a government fiercely loyal to Putin — and the Nemtsov family has criticized the investigation for not focusing on who ordered and planned the murder."Dadayev and his fellow Chechens were convicted of killing Nemtsov in late June. At the time, his daughter, journalist Zhanna Nemtsova, noted that no high-profile Chechen officials were ever questioned about the case. Copyright 2017 NPR. To see more, visit http://www.npr.org/.