That list is just a list of incidents of police violence, not protest-related, many from before 2020, and some not even in the US.

I'm not disputing whether American police are violent; we have another example from yesterday: an unarmed woman killed by police.

I'm disputing the claim that the response would have been more aggressive at a leftist protest. Thousands of National Guard troops, in addition to police in riot gear, were dispersed to clear the Capitol. They did so. Less violence was required to do so, because the protestors complied.