Do you have a citation for that because I have only ever seen research pointing to the opposite.
https://www.washingtonpost.com/politics/2020/10/16/this-summ...
As far as I know, the body count of police killing unarmed black people far outstrips any body count of BLM protests.
> The Post’s data shows police fatally shot 13 unarmed Black men in 2019.
https://www.usatoday.com/story/news/factcheck/2020/06/23/fac...
> Over the past five years there has been no reduction in the racial disparity in fatal police shooting victims despite increased use of body cameras and closer media scrutiny, according to a new report by researchers at Yale and the University of Pennsylvania.
...
> Among unarmed victims, Black people were killed at three times the rate (218 total killed), and Hispanics at 1.45 times the rate of white people (146 total killed).
https://news.yale.edu/2020/10/27/racial-disparity-police-sho...