US mainstream news outlets like CBS News with actual reporters on the ground at the time: https://www.cbsnews.com/news/there-was-no-tiananmen-square-massacre/
Classified US communications with assets on the ground: https://wikileaks.org/plusd/cables/89BEIJING18828_a.html
Image Analysis
Don’t forget how the Chinese used smallpox infected blankets to kill off indigenous populations in the Americas. /S