Russian opposition activists walk during a march in memory of murdered Kremlin critic Boris Nemtsov in central Moscow on February 25, 2018. 
The 55-year-old former first deputy prime minister under Boris Yeltsin was shot in the back several times just before midnight on February 27, 2015 as he walked across a bridge a stone's throw from the Kremlin walls. / AFP PHOTO / Yuri KADOBNOV        (Photo credit should read YURI KADOBNOV/AFP/Getty Images)