The march was organized by neighborhood Actions to Stop violent By protesters . Protesters marched from Manhattan 's Union Bridge and across the Brooklyn Bridge where they partially blocked traffic . Marched from Manhattan 's Union Bridge and across the Brooklyn Bridge where they partially blocked traffic . Police say an off - duty police officer driving home on the bridge was assaulted by two policemen when he jumped out of his vehicle to investigate .
The march was organized by National Actions to Stop Murder By Police . Protesters marched from Manhattan 's Union Square and across the Brooklyn Bridge where they partially blocked traffic . Marched from Manhattan 's Union Square and across the Brooklyn Bridge where they partially blocked traffic . Police say an off-duty police officer driving home on the bridge was assaulted by two protesters when he got out of his vehicle to investigate .