In 2016 and 2017, 25 Americans, including CIA agents, who worked in the U.S. Embassy in Cuba suffered serious brain injuries causing impaired vision and memory loss among other persistent problems. At least 15 American officials in China suffered unexplained brain trauma soon after. As we first reported in March, the FBI is now investigating whether these Americans were attacked by a mysterious weapon that leaves no trace. Mark Lenzi is a State Department security officer who worked in the U.S. Consulate in Guangzhou, China. He says that he and his wife began to suffer after hearing strange sounds in their apartment. Mark Lenzi believes he was targeted because of his work. He uses top secret equipment to analyze electronic threats to diplomatic missions. It was a weapon," [said Lenzi]. "I believe it's RF, radio frequency energy, in the microwave range." A clue that supports that theory was revealed by the National Security Agency in 2014. This NSA statement describes such a weapon as a "high-powered microwave system weapon that may have the ability to weaken, intimidate, or kill an enemy over time without leaving evidence." The statement goes on to say "... this weapon is designed to bathe a target's living quarters in microwaves." The NSA disclosed this in a worker's compensation case filed by former NSA employee Mike Beck. In the 1990's Beck and an NSA co-worker were on assignment overseas. Years later, he says they developed Parkinson's Disease at the same time.