Jails are full of people who swear they didn't do it, too. That doesn't mean that you should credulously believe them without doing your homework first.
My point was simply that there is no shortage of people claiming that some rule was unfairly enforced because the alternative is to admit they did something wrong. I used the most common expression of that concept but if you must, feel free to substitute, say, a bunch of divorced people in a bar ranting about how their ex caused 100% of the problems but fooled the judge.
Well, I did some further research. It's best not to generalize, as I did, based on Google result headlines. What I found was that there were many examples of calls for violence on Twitter #blacklivesmatter. I also found several articles which laid out calls for violence on Twitter by Black Lives Matter "supporters". However, I did not find any calls for violence against police officers by the official Black Lives Matter Twitter account itself.