The Suspected Chinese Spy Who Met With Trump — ProPublica

As often happens in counterintelligence cases, Liu remains an ambiguous figure: a con man, or a spy, or possibly both. People familiar with the case are suspicious about his ability to roam the world for years and his success at infiltrating high-level U.S. politics. 

 "Guys like this never do this kind of thing on their own," a national security source said. "They always do it for someone else."…

https://www.propublica.org/article/liu-tao-trump-meeting-china-investigation