Mr. Diebold shook the hand of his lawyer, Paul Keefe, and left the building a free man.

This routine was repeated throughout the day, as Ms. Bayer asked the judge to dismiss cases against 13 other defendants as well. The judge acceded to all requests, ordering that arrest records for those defendants be sealed.

The march onto the Brooklyn Bridge and the resulting arrests marked one of the high-profile moments of the Occupy Wall Street protests, which had begun two weeks earlier. While many in the crowd that took to the roadway said later they felt as if officers had escorted them there, police officials vehemently disagreed and said the marchers had been warned not to proceed.

As the bridge cases have moved through the legal system, some defendants have pleaded guilty to disorderly conduct and many have accepted an agreement whereby their charges will be dismissed if they are not arrested in the next six months.

But the district attorney’s office has also asked for outright dismissals. So far, 174 of the 686 cases in which charges were brought have resulted in dismissals. The percentage of dismissals is higher among people who were issued summonses, in a process akin to receiving a traffic ticket, compared with those who were issued desk appearance tickets, which defense lawyers said typically involved fingerprinting and photographing the recipient.