Vladlen Tatarsky was a high profile champion of the war in Ukraine, a blogger who didn't appear to be afraid to criticise the Kremlin for their shortcomings in the war.
His murder happened in a cafe in St Petersburg once owned by Yevgeny Prigozin, the head of the Wagner Mercenary Group. Tatarsky was handed a statuette which exploded, killing him, and wounding as many as 30 of his supporters.
The Russians promptly arrested a young woman Darya Trepova, an anti-war protestor, who has now been charged with terrorism. Prigozin himself has opined he didn't think the blast was the work of the Ukranian Goverment.
Another theory is that it could also be the work of Russian political infighting. Newsnight’s international correspondent Joe Inwood reports.