The police DID treat BLM protestors differently. Below is a link to a good write up on PolitiFact. The main difference lay in the initial postures. Law enforcement assumed that BLM would be violent and prepared for that in terms of gear, numbers, and deployment. Whereas, it was assumed that the Trump protestors would be peaceful, which resulted in events playing out very differently.
Watch the video on the politifact page.
https://www.politifact.com/article/2...ol-assault-co/