Obama talked at length about how violence isn't the way to resolve issues that BLM faced. He took pains to make the point that folks who plan or talk about violence against cops do a disservice to the supposed justice they seek. You can repeat the lie that he didn't talk about it but it still remains a lie. 

BLM isn't responsible for the Dallas shooter any more than pro-life groups are responsible for the PP shooter in CO Springs. The Nazis showed up in Charlottesville with shields and bats. One of their cadre ran a bunch of people over and killed one of them. THAT is what you're defending.