This is the best summary I could come up with:

Washington — The U.S. on Thursday issued new sanctions targeting four Russian officials allegedly involved in the 2020 poisoning of opposition leader Alexey Navalny, a fierce opponent of Russian President Vladimir Putin and serving a lengthy prison sentence.

Three of the four have worked with a specialized laboratory run by the Russian security service known as the FSB Criminalistics Institute.

The U.S. assessed he was the target of an assassination attempt by Russian operatives using the Soviet-era nerve agent Novichok, which Russia has used against dissidents abroad in the past.

The sanctions block the operatives' access to the U.S. financial system and make it illegal to do business with them.

Navalny and his allies have maintained his innocence and accused Russia of imprisoning him for political reasons.

His group, the Anti-Corruption Foundation, published stories exposing the vast wealth accumulated by the Russian elite, including Putin and his top allies.

I'm a bot and I'm open source!