peaceful 75-year-old protester unconscious on the ground with blood coming out of his ears, page-91

When the guy falls one of the officers goes to assist and is actually pulled away by another officer. The police weren't advancing in a single line such that if one officer broke out to render assistance it compromised their operation. You say they were "probably" protecting the building to the left from rioters and looters. Perhaps it was a quiet riot, but there's no evidence of rioting in the audio or video, so it's something of a leap to say that's what was happening. The issue seems to be police viewing the public as their enemy. If these cops were driving the tank in Tiananmen Square in 1989, would they stop or just run straight over the guy?

Reaper