A black-and-white cap emblazoned with anti-police lyrics from an N.W.A. song is sparking a freedom of speech debate in a city where tensions are rising between police and some members of the public.

Santa Ana Mayor Miguel Pulido on Wednesday defended his decision to cancel the City Council meeting a night earlier after a man sat down in council chambers wearing a hat with the phrase “(Expletive) the police.”

After Pulido saw the hat, he said he found it offensive. After the man refused to leave or take off the hat, Pulido told the public to leave the council chambers. Later, when some people chose to stay, they were threatened with arrest. The meeting was not resumed.

“We have to treat each other with respect,” Pulido said Wednesday. “I conduct the council meetings in a manner where we can get city business done. When people have profanity … I’m just not going to allow that.”

It’s unclear whether the city, or Pulido, violated the First Amendment, which prohibits the government from interfering with most speech.

Erwin Chemerinsky, dean of the UC Irvine School of Law, said he didn’t know if the hat’s profanity, or Pulido’s actions, violated any Santa Ana city law. But, he said, by closing a public meeting and urging police to arrest people for staying, Pulido “clearly overreacted.”

Citing Supreme Court case, Cohen v. California, in which the Supreme Court held that a boy had a right to have a jacket in a courthouse with the saying “(Expletive) the Draft,” Chemerinsky said the man in Santa Ana had the First Amendment right to wear the hat with that message.

“The sign offended the mayor. But he should have ignored it and gone on,” Chemerinsky said.

The man in the hat, who gave his name only as Bijan at the Tuesday meeting, is a member of CopWatch Santa Ana, a group that monitors and films local police activity. He said he was arrested recently while filming police activity.

“I came here to talk about the police abuse that I’ve experienced with the Santa Ana Police Department,” he said Tuesday night.

“I don’t feel like I have to take this off in this City Council meeting. It’s a meeting for the public and I’m allowed to be here with my hat.”

Last month, demonstrators from Santa Ana protested a police awards ceremony in the council chambers. Those protests prompted the Santa Ana Police Officers Association to say it no longer wanted to receive awards in public.

It’s unclear if the man in the hat was part of the protest or was continuing that protest Tuesday.

Santa Ana police Chief Carlos Rojas said he supported Pulido’s decision to close the council meeting.

“We didn’t want to get in a big debate with a room full of people,” Rojas said, adding that police wanted the room isolated “to deal with the problem, whether it would lead to an arrest or not.”

“We want everybody to leave so we could restore order,” Rojas said. “If the mayor doesn’t want somebody with that offensive language in the meeting, it disrupts the meeting.”

Mayor Pro Tem Sal Tinajero said Wednesday he was surprised the meeting was closed, but he supported the move. “We always have to err on the side of caution, and I think that’s what happened last night.”

The next City Council meeting is set for Oct. 21.

Contact the writer: amolina@ocregister.com