Sobyanin who, according to official results, only managed to win just over 50% of the votes. Navalny and his supporters maintained that the authorities had altered the results just enough to allow Sobyanin to cross the 50% threshold and avoid a runoff, which would have been a dramatic setback for the establishment. In the aftermath of the election, Navalny was offered a position as the fourth co-chaiman of RPR-PARNAS alongside Kasyanov, Boris Nemtsov and Vladimir Ryzhkov. Despite the authorities banning the party from participating in some regions in the 2013 regional elections – likely for political reasons – RPR-PARNAS managed to achieve another electoral success in the autumn of 2013 when co-leader Nemtsov successfully managed to win a seat on the Yaroslavl regional parliament. Nemtsov's victory meant that the party won the right to run in state legislative elections without having to collect signatures, since it held a seat in one of Russia's regional parliaments. In turn, this made RPR-PARNAS the only "non-systemic" opposition party that had automatic access to the ballot in legislative elections. In the concurrent September 2013 gubernatorial elections, all of the party's candidates were disqualified from running by the authorities. It was in 2013 that Nemtsov also published a report on the upcoming 2014 Winter Olympics which were planned to be held in Sochi, Russia. He provided evidence there had been massive embezzlement by government officials, asserting that it amounted to about 50-60 percent of the stated final cost of the sporting event. Assassination of co-leader Nemtsov One of the party's co-leaders at this time was Boris Nemtsov, the party's most influential and talented mediator and a leading Russian opposition figure. Nemtsov had been one of Russia's leading economic reformers in the 1990s and also served as first deputy prime minister under President Boris Yeltsin. Nemtsov was assassinated in Moscow on 28 February 2015, being shot by an attacker in a car while on a bridge by the Kremlin. He died hours after appealing for support for an upcoming protest in Moscow against the war in Ukraine, and in a recent interview, Nemtsov had said he feared president Putin would have him killed because of his opposition to the war in Ukraine. Ukrainian president Petro Poroshenko described Nemtsov as "a bridge between Ukraine and Russia" and added "the murderers' shot has destroyed it. I think it is not by accident". In the aftermath of the assassination,