(UK scientists concluded that in 2002 the Russian government used carfentanil to attack Chechen rebels who had taken over a Moscow theater, dispersing it through the building’s air duct. At least 170 people died, including 121 hostages. The UK scientists based their conclusions on tests of items of clothing and blood belonging to British citizens who were near an exit and thus among the hostages revived by a Russian assault team that day. The Russian government has never commented on what it pumped through the theater beyond to say that it was a “mixture based on derivatives of fentanyl.”)
