The law frowns on police use of pepper spray against nonviolent demonstrators.

More than a decade before last week's videotaped incident at UC Davis, a federal appeals court ruled in the case of North Coast logging protesters that officers can legally use the caustic chemical only to prevent harm to themselves or someone else.

The California Commission on Peace Officer Standards and Training, which advises police agencies and officers statewide, says pepper spray "can have very serious and debilitating consequences," and "should only be generally used as a defensive weapon" and never to intimidate or retaliate.

Friday's pepper-spraying of students as they sat on the ground, their arms linked and heads bowed, has drawn criticism from UC President Mark Yudof, an apology from Davis Chancellor Linda Katehi, and the suspension, with pay, of two officers and the campus police chief.

On Tuesday, Yudof asked the acting police chief to get criminal charges dismissed against 10 protesters involved in Friday's demonstration and said the school would pay the demonstrators' medical bills. He also named William Bratton, a former Los Angeles police chief, to direct a review of the pepper-spray incident.

No guarantees

Still, the outcome of any future lawsuit is not a foregone conclusion.

Rich Pedroncelli/AP

"Using pepper spray on persons who are wholly passive seems like excessive force," said Rory Little, a law professor at UC Hastings in San Francisco. But if officers testify that they felt threatened, he said, "it's going to be a jury question" as to whether they overreacted.

"You have to look through the eyes of a reasonable officer at the scene, and not with 20/20 hindsight," said David Klinger, who teaches criminology at the University of Missouri-St. Louis.

While the videotape looks damning, he said, it might be different if police had information that demonstrators planned to attack any officer who tried to arrest them.

Their cautions were illustrated in the leading West Coast case on the issue. It arose in Humboldt County in 1997, when officers swabbed liquid pepper spray in the eyes of protesters who chained themselves together at the headquarters of Pacific Lumber Co. and fastened themselves to logging equipment. Those who refused to move were then sprayed in the face at close range.

A jury in San Francisco deadlocked 4-4 on whether the officers violated the demonstrators' rights. U.S. District Judge Vaughn Walker then dismissed the case, saying no reasonable juror could find excessive force.

Guidelines set

The Ninth U.S. Circuit Court of Appeals reinstated the suit in 2000 and set standards for future pepper-spray cases in the federal courts of California and eight other Western states.

Plaintiffs may be able to prove excessive force, the court said, if they can show they "posed no immediate threat to the safety of anyone" and if police had less painful or intrusive alternatives. Jurors, the court said, should also consider the seriousness of the plaintiffs' alleged crime and whether officers were facing an emergency.

The case then went through two more trials before a jury in 2005 unanimously found the officers had acted with excessive force and awarded eight plaintiffs nominal damages of $1 each.

"Reasonable people can differ" in assessing officers' response to demonstrators, said Little, the Hastings professor and a former federal prosecutor. Courts have ruled, he noted, that "some degree of force can be used to remove even peaceful protesters."

In a 1994 case, for example, the same federal appeals court upheld police use of a "pain compliance technique" - two sticks and a cord that were gradually tightened around a person's wrist - to remove demonstrators who were blocking an abortion clinic.

Humboldt County officers cited that ruling in defending their use of pepper spray. But the court said the antiabortion protesters had threatened clinic staff and patients, and were subjected to increasing levels of pain that ended when they complied - unlike the "immediate and searing pain" that lasts beyond the initial dose of pepper spray.

'Chemical cattle prod'

Pepper spray violates constitutional standards when it's "used as a chemical cattle prod on nonviolent protesters," said Margaret Crosby, an American Civil Liberties Union lawyer who took part in the Humboldt case.

But Walnut Creek attorney Harry Stern, who has represented police officers, said pepper spray represents "a very, very low use of force" that may be justified when officers face resistance.

"I probably share most people's immediate reaction" to the UC Davis incident, Stern said. "But I know enough about these cases to reserve judgment."