© Robert Stolarik for The New York TimesPolice officers made arrests on Liberty Street near Zuccotti Park in Lower Manhattan in March during an Occupy Wall Street protest.
During Occupy Wall Street protests New York police officers obstructed news reporters and legal observers, conducted frequent surveillance, wrongly limited public gatherings and enforced arbitrary rules, a group of lawyers said in a lengthy report issued on Wednesday.

The group, called the Protest and Assembly Rights Project, which included people involved with the law clinics at New York University School of Law and Fordham Law School, said that they had cataloged hundreds of instances of what they described as excessive force and other forms of police misconduct said to have taken place since September, when the Occupy Wall Street movement began.

Although the report referred to some well-known events, including Deputy Inspector Anthony Bologna's use of pepper spray, it also detailed specific instances of alleged misconduct that had not appeared in news reports.

For instance, the report described a cafe employee stepping out of his workplace on Sept. 24 and using a camera to document arrests near Union Square before being confronted by a senior officer. The report went on to state:
"Video then shows the officer grabbing the employee by the wrist, and flipping him hard to the ground face-first, in what was described as a 'judo-flip.' The employee stated that he was subsequently charged with 'blocking traffic' and 'obstructing justice'."
In a more recent episode, Sarah Knuckey, a law professor and one of the report's authors, said she witnessed a police commander grab a man who was complaining of an injured shoulder while being arrested during a student march on May 30. Ms. Knuckey said that the commander repeatedly shoved the man's shoulder while handcuffing him, then cursed and accused him of lying, when he shouted in pain. Shortly afterward, Ms. Knuckey said, emergency medical technicians determined that the man had a broken clavicle.

The report complained that there had been "near-complete impunity for alleged abuses" and said that the conduct amounted to a "a complex mapping of protest suppression."

There have been hundreds of gatherings and marches and more than 2,000 arrests in New York City since the Occupy protests began last fall. During that time, Ms. Knuckey said, many police officers had acted in an exemplary fashion. But, she added, multiple episodes of intimidation had created a pattern of disturbing and unlawful behavior.

A police department spokesman did not immediately respond to a request for comment. The report's authors said that senior members of the police department cited continuing litigation in declining to talk with them.

In May, an assistant deputy commissioner in the police department's legal bureau wrote to the authors, saying that the Police Department considered its actions lawful and added that the police "had accommodated on an almost daily basis since last fall numerous large groups of demonstrators and marchers, all with virtually no cooperation, notice or advance planning from Occupy Wall Street representatives."

In addition to detailing 130 instances of what was described as excessive or unnecessary force, the report said that officers often stopped news reporters or legal monitors from witnessing such events.

The report also describes instances in which the authors say officers have chilled First Amendment expression through near constant surveillance with video cameras and by sometimes questioning protesters about political activities. The report also described a common practice of preventing protesters from gathering in areas that are open to the public, like parks, plazas and sidewalks.

"Attempts by protesters to understand the basis for the closure, or obtain clear directions from the police are most often ignored or answered perfunctorily," the report stated. "Sometimes queries are answered with an arrest threat or an arrest."

The authors called for the city to establish an inspector general to oversee the police department, a review of the city's response to the protests, the prosecution of officers found to have broken laws and the creation of new guidelines for policing protests. If the city did not respond, the authors said, they would ask the United States Department of Justice to investigate their complaints.