Kim Jong Nam's assassins killed him with a banned chemical weapon, Malaysian police revealed Friday. The country's police chief said toxicology reports on swabs from the face and eyes of the exiled North Korean found VX nerve agent, which the BBC notes is classed as a weapon of mass destruction by the United Nations. He said that one of two women believed to have rubbed the extremely toxic substance on Kim's face with their hands suffered from vomiting after the attack. The New York Times reports that VX agent can be created by mixing two compounds—and police suspect the two women put the substances on Kim's face, one after the other, to create a deadly dose.
The police chief said the airport where Kim was attacked is now being decontaminated. North Korea—which is widely suspected to have been behind the killing of leader Kim Jong Un's half brother—never signed the Chemical Weapons Convention that banned VX, the AP notes. Pyongyang denies involvement and says Malaysia's investigation is full of "holes and contradictions." The father of one of the two women being held, Vietnamese citizen Doan Thi Huong, tells the Times his daughter trained as a pharmacist and he has seen little of her in recent years. (Police say that after Malaysia refused to give Kim's body to North Korean diplomats, somebody tried to break into the morgue.)