Skripal isn’t the only former Russian spy to be poisoned in the U.K.: In November 2006, Alexander Litvinenko, an FSB officer-turned-dissident, died in a London hospital after drinking a cup of tea laced with polonium-210, a highly radioactive substance. An inquiry by British investigators concluded that his death was the work of the Russian state and was probably greenlighted by Putin himself.

Karpichkov was one of two former double agents who spoke with NBC News about their anxieties in the wake of the Skripal poisoning.

Victor Makarov, another former KGB agent, fears for his safety but lives in a much less guarded way than Karpichkov.

via NBC Russian ex-spy says he was on Kremlin ‘hit list’ along with poisoned Skripal