A physics major, a Ph.D. student in Spanish literature and a young woman accused of assaulting police with a bicycle were among those who packed Pittsburgh Municipal Court yesterday for the first batch of hearings for people swept up in last week's G-20 arrests.

David Japenga, 21, was held for trial on charges of smashing more than $15,000 worth of windows in Oakland. Two other men pleaded guilty to disorderly conduct and agreed to pay $100 fines. Six defendants had their cases postponed and can have all charges dropped if they complete community service, and another 43 hearings were put on hold as defense attorneys and prosecutors collect evidence.

Police made nearly 200 arrests during the summit, including 51 Pitt students, and many in the courthouse yesterday accused law enforcement officials of grabbing innocent bystanders in their search for lawbreakers.

"I'm extremely upset," said Chris Nielsen, 28, who moved from California to Pittsburgh a month ago to begin his doctorate in Spanish literature at Pitt. "I think there was an excessiveness of force."

Standing before television cameras and wearing brown sandals, a brown sports coat and a professorial beard, Mr. Nielsen said he was riding his bike home Thursday around 6 p.m. when he spotted a line of police officers at the corner of Cypress Street and Baum Boulevard. He said the police moved toward him, and he shouted, "I'm moving back. Don't touch me!"

He said an officer struck him with a baton, knocking him down. He was then arrested and charged with failure to disperse and obstructing a public highway.

The charges will be dropped if he completes 50 hours of community service.

Mr. Japenga, another Californian who recently moved here, has been held in jail since the summit, and he was brought before District Judge Eugene L. Zielmanski in shackles and a red Allegheny County Jail jumpsuit.

Mr. Japenga is accused of using a U-shaped bicycle lock to attack Citizens Bank, Quiznos and the Irish Design Center, all on South Craig Street, around 11 p.m. Thursday, shortly after police in riot gear broke up a large crowd at nearby Schenley Plaza.

Deputy District Attorney Rebecca Spangler said the damages to the three businesses amounted to $14,740.

A state trooper testified that he saw someone fitting Mr. Japenga's description moving in and out of a large crowd to break windows. Many people were wearing masks and black clothing, but Mr. Japenga had a distinctive height, body size and gait, Trooper Boyd Wass testified.

Trooper Wass, who was undercover, said he lost sight of Mr. Japenga for several minutes but recognized him again on the lawn of the Cathedral of Learning, even though Mr. Japenga had changed into a yellow shirt. The trooper called for Pittsburgh police officers to make the arrest.

Patrick K. Nightingale, Mr. Japenga's attorney, disputed the reliability of the identification.

"He's another one of those people who were caught at the wrong time in the wrong place, exercising their First Amendment rights," Mr. Nightingale said of his client.

Judge Zielmanski agreed to drop a conspiracy charge, but he held Mr. Japenga for trial on three counts of criminal mischief, possessing the instrument of a crime and providing a false identification.

When he was arrested, Mr. Japenga identified himself as Eric Blair -- the given name of George Orwell, author of "1984."

Throughout the morning yesterday, the courthouse resembled both a Lawrenceville hipster bar or a Friendship Park drum circle, with dozens of young people in designer clothing or ripped jeans and dreadlocks.

There was also anger in the air.

"We're innocent," said Luke Rudkowski, 23, of New York City, who pleaded guilty to a disorderly conduct charge to avoid returning to Pittsburgh for future court appearances. "I don't think this is justice at all."

He and Lee Iovino, 23, of Chicago, were arrested Friday night in Oakland after police encircled a crowd on the cathedral lawn. At the time, Mr. Rudkowski said, he and others had been trying to obey a dispersal order, and he used a bullhorn to shout at police, "Where do we go? Where do we go?"

He said officers struck him with batons and threw him to the ground, where he was handcuffed.

A hearing for 22-year-old Lauren Wasson of Garfield was postponed until Oct. 21. She is accused of striking a police officer with her bicycle and faces a charge of aggravated assault.

"We think it should be dismissed, but we'll see," said Mike Healey, an attorney for Ms. Wasson and several other people who were arrested during the G-20.

William Taylor, 19, a Pitt sophomore studying physics, said police falsely accused him of resisting arrest at Thursday's large gathering in Schenley Plaza.

He said an officer grabbed his backpack and pulled him behind a line of police. He was then thrown to the ground and arrested.

An affidavit of probable cause said Mr. Taylor had pushed up against police officers' riot shields, but he denied the accusation.

"I didn't pose any threat," he said. His hearing yesterday was also postponed.

On Tuesday, Allegheny County District Attorney Stephen A. Zappala Jr. said he would drop charges against at least four Pitt students, and his office is reviewing evidence against dozens of other students who may have erroneously been caught up in mass arrests last week.

Many Pitt students are furious about police actions on their campus. Today at 5:30 p.m., several groups, including the university branch of the ACLU and the Thomas Merton Center's Anti-War Committee, are gathering at Forbes Avenue and Bigelow Boulevard to hold a demonstration.

"As a community in shock, we need to know who gave unconstitutional orders to the police and why," Pitt ACLU President Genevieve Redd said in a news release.

City officials have defended how police handled arrests, saying they gave lawful dispersal orders and were attempting to prevent further property damage.

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