The inquest into the death of another Kremlin critic's death has recorded a verdict of unlawful killing, ie murder. Although this took place three years ago, the week after the Salisbury poisonings, the inquest has only just been held, for some reason. The crime scene was apparently manipulated to attempt to make it look like suicide.

Mr Glushkov was a close friend of oligarch Boris Berezovsky, a vocal critic of Mr Putin, who was found hanged at his Berkshire home in 2013.
An inquest into Mr Berezovsky's death recorded an open verdict.
https://www.bbc.co.uk/news/uk-england-london-56695489