My office filed a lawsuit against the mayor of the city of New York, the city of New York and the leadership of N.Y.P.D.

The New York State attorney general sued the New York City Police Department on Thursday over what she said were widespread abuses in how officers handled the protests that erupted last summer after the killing of George Floyd in Minneapolis.

The lawsuit, filed in federal court in Manhattan, marked the first time in history that the state attorney general has sued a police department, according to Ms.

An investigation by the attorney general’s office found that police officers beat protesters with batons, rammed them with bicycles, used a dangerous containment strategy called kettling, and arrested legal observers and medics without proper justification.

“A court process and the added bureaucracy of a federal monitor will not speed up this work,” he said in a statement on Thursday after the lawsuit was filed.

James said at a news conference on Thursday that officers’ behavior at the protests demonstrated a pattern of illegal and harmful practices that the mayor and Police Department had failed to prevent through discipline, policies and training.

James, the state’s top prosecutor, has not brought charges against any of the officers involved in the protests, and neither have the police, local prosecutors nor the city Department of Investigation.

Shea had said that his department had executed its protest plan “flawlessly,” and the mayor had said the police’s uses of kettling to contain protesters were “justified.” (The mayor, in December, banned police from using the tactic.).

James has called for control of the Police Department to be stripped from the mayor and given to an independent panel.

She said her investigation had found “an egregious abuse of police power; rampant, excessive use of force; and leadership unable and willing to stop it.”.

Gideon Oliver, a civil rights lawyer who is representing several demonstrators who have filed lawsuits against the police, said the attorney general’s lawsuit built on years of efforts by civil rights lawyers to address “the city’s wildly inadequate responses to these problems that have been going on for a very long time.”.

“They sent cops out to police unprecedented protests and violent riots with no plan, no strategy and no support,” he said.

The lawsuit filed Thursday mentioned abuses at protests that continued through the November election.

In December, the city Department of Investigation said the Police Department’s botched handling of the protests was emblematic of a systemic failure to recognize the First Amendment rights of protesters.

Smith, who sued the Police Department, described the attorney general’s lawsuit as historic and an “indictment against the largest police force in America for its culture of taking opportunities to target those that they are sworn to protect.”.

The Legal Aid Society, the city’s largest public-defender group, and the New York Civil Liberties Union represent 11 people who have sued the city over the protests

The organizations said in a joint statement that they hoped the attorney general’s lawsuit would be “the beginning of a serious reckoning over police violence and militarized use of force against protesters, especially people of color, and a check on the impunity many officers have come to see as their right.”

Jumaane Williams, the city’s public advocate, said that the lawsuit was not enough on its own to break the cycle of police abuse and public outcry