Harry Truman, I am glad you were able to learn and apply reasoning so you are no longer theist, with the aid of these boards. I invite you to use the same tools for all news you hear about.

Black Lives Matter, (BLM) while not a perfect organization that can perfectly account for all people that use their name, the majority of the large amount of information, coverage, and the organization's own rules and standards point to BLM being a peaceful protest group peacefully working to improve the lives of black people.

Read the organization's (BLM) website, read well regarded news sources known for ethical reporting standards that cover BLM. Consider both sides of every issue. While it is good to consider what your friend told you, also know that he may be uninformed on the issue, perhaps your friend saw a black person with a black bandana and just assumed it was a member of BLM. Also know the actions of one person does not represent the whole.

Life is rarely simple, you have to look at the overall body of evidence before you decide something, especially if the issue is sensitive and controversial.

It is in my experience, and I think many people would agree with me, that the overall body of evidence for and against BLM concludes that BLM is by and large a peaceful group working to improve the lives of black people, and they are a group that should be supported in their efforts by reasonable people that care about other people.