I attended the National Moment of Silence in SF, a decent sized crowd for only a day to organize. It was good and peaceful and by that I mean there were no cops. It sounds like the NY rally was less peaceful, in other words the cops showed up to cause trouble.
One of the many people that spoke. She's been at this for 8 years now after her Son shouted run to a friend and the cops unloaded 14 rounds into him. He was of course unarmed.