This city was treated to a most unusual political trial in June, when 12 anarchists appeared in Manhattan Criminal Court charged with "masquerading in public" on May Day 2000. It was the first prosecution in decades under a 150-year-old state law that Mayor Rudolph Giuliani dusted off two years ago to block a Ku Klux Klan rally.

Thanks to an earlier court decision, the non-jury trial gave the anarchists a rare opportunity to discuss and defend their beliefs in court--including the black clothing and bandannas that have become common at protests. But perhaps most important, officers who took the witness stand admitted what critics have long charged--that New York police allowed out-of-town police to attend rallies here and videotape them to profile activists in preparation for protests in other cities. Judge Ellen Coyne's ruling is expected in mid-August.

The case concerns the arrest of a group of anarchists just before an annual May Day

NYPD's masked marauders. ERIC LAURSEN

march. Police amassed along the parade route had received a briefing from an NYPD "disorder expert" that the crowd could include "WTO-Seattle-type protesters." A police surveillance videotape shows that the anarchists, some of whom were wearing bandannas and some not, were standing quietly when they were suddenly jumped by police, wrestled to the ground and arrested.

The defendants were held in jail for as long as 36 hours on a range of charges including violation of the mask law, which prohibits two or more persons from "congregating" in public while wearing masks to obscure their identities. The vaguely worded statute was adopted back in the 1840s, when the state was trying to suppress the "Rent Wars," a series of tenant farmer uprisings against landlords. The mask law languished for many years, but other cities facing large-scale political protests--including Philadelphia, Windsor, Ontario and Quebec--have adopted their own anti-mask laws.

"If Judge Coyne comes down in favor of the anarchists being able to participate in political events while wearing masks," says Beth Haroules of the New York Civil Liberties Union, "the message to the city is they shouldn't be using loitering laws to clear the streets of people expressing political beliefs." The NYCLU has filed a separate request with federal Judge Harold Baer to declare the mask law unconstitutional.

Attorney Ron Kuby, who represents the anarchists, compares the case to those of Chinese, South Korean and Iranian activists who have worn masks at demonstrations in those countries for fear of reprisal. "At least some of these defendants were aware that there was ongoing surveillance of their movement in preparation for the [then upcoming] Republican National Convention," which Kuby says justifies their wearing masks. "Indeed, the Philadelphia police were there [at the May Day rally] taking pictures of them."

At trial, Kuby grilled Michael Fox, who was in charge of the arrests, and Thomas Graham, a deputy inspector with the NYPD's disorder control unit, about their own knowledge of anarchism. Neither was familiar with the leading anarchist thinkers Kuby mentioned Kropotkin, Bakunin, Berkman--and Graham testified that a 60 Minutes segment was his principal source about the movement.

Fox also acknowledged for the first time that the NYPD and other police departments have been cooperating to profile demonstrators whom they suspect of being "Seattle-type" activists. This included officers from Philadelphia and Morristown, New Jersey, some of whom were recognized by the defendants from those cities, and who were in New York videotaping the anarchists before they were arrested.

Although the defendants expect an acquittal, that alone will not eliminate the mask law as a threat to activists. "Even if we can prove to them that prosecution is fruitless in these cases, that doesn't prevent the police from making an arrest," Kuby notes. "Either the district attorney has to tell them that it's not prosecutable, or the new mayor of New York has to say 'don't do it.' "

This year's May Day was again marred by arrests when police charged a group of activists who were performing street theater at a march in support of immigrant workers. Police arrested five--one for violating the mask law. The NYCLU is collecting activists' arrest stories going back to 1998 for a possible class-action lawsuit against the NYPD.

Haroules is optimistic about the anarchists' chances of an acquittal, noting that the courts have become "a lot more jaundiced in their evaluation of the tactics the police are using." But for her, the real goal is to change police action: "Unfortunately, that stance hasn't filtered down to the behavior of the cop on the street."