"Our Joint Terrorism Task Force is involved in this simply because the victim here is from another country and it just kind of makes sense that our terrorism guys would take a look a look at this," FBI Special Agent in Charge James Davis said.

Cyanide can be made from plants in very small amounts. It can be a gas, liquid or powder. It prevents the body from using oxygen and therefore is more harmful to the heart and brain than other organs.

"It was used in concentration camps in World War II and by Saddam Hussein against the Kurds in the 1990s."

Officials said cyanide can be used as a terrorist weapon if it is dumped in water put in food, sprayed as a gas, or many other methods.

The investigation is continuing.