Its Antifa. Did you expect the police to interfere with them as they go about their work? If the police had interfered on the part of the man and old girl they would have been fired within the hour. As far as Antifa attacking the young girl, they would have attacked her if she had been an elderly lady. You are not the only one who has wondered why President Trump has not declared them a terroristic organization. Do you know the History of Antifa?
They are commies. Several countries have kicked them out. That is all I know.