In a party-line vote, Arizona Senate Republican panelists approved a House bill, HB 2309, that creates a new crime making it a felony if a person, acting with seven or more others, causes injury or property damage while engaging in a riot or an unlawful assembly.

The bill’s sponsor, Rep. Bret Roberts, says the bill is meant to deter protest turnout if Arizonans think that there might be some violence. 

"This bill is intended to give individuals that choose to partake in what's supposed to be peaceful protest to give them a moment of pause and ask themselves, 'Do I want to attend this event?'" Roberts said. 

That admission alarmed attorney William Knight. He says it’s already a crime to riot or assault a police officer, and what this bill does is “chill people from engaging in protected speech.”

Marilyn Rodriguez of the American Civil Liberties Union says another problem is that the bill leaves it up to police to decide when a demonstration becomes an "unlawful assembly.''

Knight says this will invite lawsuits, like the kind already filed against Phoenix police for their actions arresting those at Black Lives Matter protests.

The bill now heads to the full Senate.