A warning that people see before filing complaints against Los Angeles police officers creates a barrier to free speech, the California Supreme Court ruled today in a long-running lawsuit over the language.

The high court ruled 6-1 in favor of the city of Los Angeles and against the union that represents its police officers in finding that the admonishment describing penalties for filing false has the potential to deter “citizens from filing truthful (or at least not knowingly false) complaints of police misconduct”.

The warning exhibits “numerous characteristics that, considered together, sufficiently burden a protected form of speech — namely, truthful (or at least well-intentioned) complaints of police misconduct — so as to warrant heightened constitutional scrutiny,” Associate Justice Joshua Groban wrote in the majority opinion.

The ruling turned on a 1995 law that sought to create consequences for false claims against police officers: Anyone filing a complaint against an officer could face criminal charges if they knowingly sign a false report.

At the LAPD, officials went further, demanding that complainants affirm, in bold font and all capital letters, that they understand the potential penalties.

“IT IS AGAINST THE LAW TO MAKE A COMPLAINT THAT YOU KNOW TO BE FALSE,” the LAPD form reads. “IF YOU MAKE A COMPLAINT AGAINST AN OFFICER KNOWING THAT IT IS FALSE, YOU CAN BE PROSECUTED ON A MISDEMEANOR CHARGE.”

The court found that the warning is biased in favor of the police because witnesses who make false statements in defense of an accused officer would face no charges for lying.

“While the Legislature had a legitimate and significant interest in remedying the harmful effects of abusive false claims of police misconduct, (the law) is not narrowly tailored to meet those objectives,” Groban wrote. “Instead, the statute establishes an ill-defined, asymmetrical criminal provision that is accompanied by an unusual admonition requirement.”

The Los Angeles Police Protective League, the union representing LAPD officers, argued that the form is constitutional and necessary to prevent false complaints that would tie up an officer’s career.

The decision reversed a California appellate court ruling in this case and a 2002 California Supreme Court decision in a related case, both of which agreed with the police union that the warning passed constitutional muster.

California law is now in line with multiple federal court rulings, which found that the warning violates the First Amendment.

“It takes tremendous courage for victims and witnesses of police misconduct to come forward and seek justice and accountability,” attorney Matt Nguyen of the firm Cooley LLP, who represented civil rights nonprofits at oral argument in the case, said in a written statement. “A resounding majority of the California Supreme Court made clear today that speaking truth to power is a fundamental right protected by the First Amendment.”

In a dissent, Associate Justice Goodwin Liu said the law and the warning are “no more unconstitutional than laws that make it a crime to commit perjury, file a false police report, submit a false document to a public agency, or lie to a government official concerning an official matter.”