Strange and terrible things seem to happen to people who testify against the Kremlin.
The latest example, of course, is former State Duma deputy Denis Voronenkov, who defected to Ukraine last year and was shot dead in downtown Kyiv yesterday.
Last month, Voronenkov told Ukrainian prosecutors that ousted President Viktor Yanukovych had asked Russia to send troops into Ukraine.
And then there is the case of Nikolai Gorokhov, a lawyer representing the family of the deceased Russian whistle-blower Sergei Magnitsky. Gorokhov was critically injured this week after falling several stories from his apartment window.
And according to a report in The Daily Beast, he was a witness for the U.S. Justice Department in a money-laundering case involving Russia.
And there's Aleksandr Perepilichny, a healthy 44-year-old Russian emigre who collapsed and died while jogging in Surrey, England, back in 2012.
An autopsy later found traces of the rare toxic plant gelsemium, a poison used by assassins, in his stomach.
And guess what? At the time of his death, Perepilichny was assisting Swiss authorities in a money-laundering probe involving Russia.
And of course, there is the famous case of Aleksandr Litvinenko, who died after drinking tea laced with the rare radioactive isotope polonium at a hotel in downtown London.
At the time of his death, Litvinenko was preparing to testify in a Spanish investigation into ties between the Russian authorities and organized crime.
After the news of Voronenkov's assassination broke yesterday, a Kremlin spokesman told reporters that Vladimir Putin planned to attend a play titled "The Latest Victim" that evening.
Take from that, what you will.