The assassination of Boris Nemtsov, a Russian politician opposed to the government of Vladimir Putin, occurred in central Moscow on Bolshoy Moskvoretsky Bridge at 23:31 local time on 27 February 2015. An unknown assailant fired seven or eight shots from a Makarov pistol; four of them hit Boris Nemtsov in the head, heart, liver and stomach, killing him almost instantly. He died hours after appealing to the public to support a march against Russia's war in Ukraine. Nemtsov's Ukrainian partner Anna Duritskaya survived the attack as its sole eyewitness.The assassination was met with worldwide condemnation and concern for the situation of the Russian opposition. Russian authorities also condemned the murder and vowed to conduct a thorough investigation.

On 8 March 2015, Russian authorities charged Anzor Gubashev and Zaur Dadaev, both originating from the Northern Caucasus, with involvement in the crime. According to Russian authorities, Dadaev confessed to involvement in the murder. However, he later retracted his statement, as extracted by torture. Three more suspects were arrested around the same time and, according to Russian media, another suspect blew himself up in Grozny when Russian police forces surrounded his apartment block.