There's no evidence of businessman Bill Browder being involved in the alleged murders. But there is plenty of evidence about state-controlled media being used to circulate disinfo - for example in the Skripals case, pro-Kremlin outlets stated they were poisoned by either the USA or the UK or they just overdosed. Also, this is not the first time Russia is blaming Bill Browder - in July president Vladimir Putin said that Browder allegedly made a $400-million donation to Hillary Clinton’s 2016 election campaign and the money was stolen from Russia through tax evasion, a claim that was quickly debunked by the media.
The CEO of Hermitage Capital, once the largest investment firm in Russia, fell afoul of the Russian government in 2005 after exposing the details of a vast $230-million corruption scheme involving many high-ranking Russian officials. While investigating the corruption scheme, Hermitage Capital’s tax lawyer Sergei Magnitsky was detained and imprisoned. He died in prison in 2009, at the age of 37, after what Browder says was torture and ill-treatment in detention. To commemorate Magnitsky, USA named the act that restricts the travel and freezes the assets of people who have violated human rights The Global Magnitsky Act.