> With the dearth of physical evidence, an objective conclusion will likely remain out of reach. Something definitely happened, and something bad. But to the extent of grinding up the bodies of 10,000 civilians into meat patties and hosing them down the drain bad? It is likely that we will never know the answer to that.

I disagree. These events are still within living memory, so most of the actual people who were tasked with suppressing the protests and cleaning up afterwards can still theoretically be interviewed. Given the scale and brutality, at least some of them likely feel shame for participating and would testify honestly help clear their consciences (e.g. https://www.nytimes.com/2019/05/28/world/asia/china-tiananme...). Many others may have hidden diaries or other records (e.g. https://www.nytimes.com/2019/05/30/world/asia/tiananmen-squa...). These events also happened in a dense urban area, so there were many uninvolved witnesses. If the political situation allowed all these accounts to be collected and cross-checked, I think we'd know these answers.