One night in January, Abel Sanchez decided to visit his brother-in-law; by morning, he would be arrested, released and rushed to Yale-New Haven Hospital for injuries he sustained when he was allegedly beaten by the arresting officer.

Now, Sanchez is joining six other New Haven residents in a federal civil rights lawsuit contending they were assaulted by Officers Dennis O’Connell and Maturo — whose first name has not been released to press — of the New Haven Police Department.

The lawsuit, which the plaintiff’s lawyer and supporters announced at a press conference and rally Thursday, also names the city and senior officials of the NHPD as defendants, for failing to discipline the officers after complaints were filed with the Civilian Review Board and the Department’s Internal Values and Ethics office.

The plaintiffs are suing for a total of $9.5 million, plus unnamed punitive damages and legal fees. The plaintiffs’ lawyer, Paul Garlinghouse, said the city needs to be held accountable for its inaction.

“It is the law that when the city does not investigate so many claims, it is demonstrating deliberate indifference — which is actionable,” he said.

City spokeswoman Jessica Mayorga said in an e-mail that the NHPD will look into the allegations.

“The New Haven Police Department takes all complaints and concerns very seriously,” she wrote. “The Department’s administration is committed to the community and will be sure to look into what may or may not have occurred concerning these allegations.”

On Tuesday, immigrants rights group Unidad Latina en Accion, which filed the suit on behalf of the defendents, and local grass-roots organization People Against Injustice organized a rally on the steps of the federal courthouse on Church Street demonstrating in support of the lawsuit, and calling for an end to police brutality.

According to the complaint, four plaintiffs ­— Sanchez, Gustavo Morales, Jonathan Avila and Lamar Morrison — accuse O’Connell of spraying them with chemical spray and punching and kicking them in separate incidents while they were restrained. Maturo is accused of assisting in one of the beatings by spraying Avila’s parents, Noraima and Miguel Avila, with chemical spray so O’Connell could enter their home.

In the latter case, according to the New Haven Independent, Maturo and O’Connell wrote in their arrest reports that Avila and Morrison were arrested because they had “incited to riot” and threatened O’Connell.

The suit also names Francisco Ortiz, former New Haven chief of police who now heads security on Yale’s West Campus, as well as NHPD Lt. Jeff Hoffman, both of whom allegedly failed to supervise and discipline O’Connell after several complaints were filed against him.

In the complaint, which Garlinghouse filed in federal court Thursday afternoon, the city is accused of deliberate indifference for “maintaining a policy or practice of not investigating police abuse complaints sufficiently, and not taking action to stop officers from committing further acts of abuse.”

Garlinghouse said after the rally that he believes there was a pattern of misconduct on the part of O’Connell that should have been apparent to his superiors.

“This officer has a weirdly high number of complaints [filed against him], all of them abuse against minorities, all in Fair Haven,” he said. “It is a pattern that if you were supervising him, you would be very concerned about.”

Sanchez first filed this lawsuit in May, but the city never responded, Garlinghouse said.

After filing the original lawsuit, Garlinghouse said he heard complaints by other residents against O’Connell, and so decided to expand the lawsuit to include the other plaintiffs.

City corporation council — which is responsible for responding to lawsuits against the city — could not be reached for comment Thursday evening.

These are not the first complaints filed against O’Connell. Last year, IVE investigated O’Connell for improper cavity-searching of New Haven resident Dramese Fair, who was not at the rally but who has filed a separate lawsuit.

According to the New Haven Independent, Mayorga said IVE cancelled a Board of Commissioners hearing on the case scheduled for last April because they needed more time to investigate. The hearing has not yet been rescheduled.

Fair’s aunt and one of the leaders of People Against Injustice, Barbara Fair, said at the rally that all of this could have been avoided.

“If they had paid attention and disciplined officer O’Connell, we wouldn’t all be here right now,” she said to the crowd of about 30 supporters.

Her son, Sheldon Tucker, questioned the priorities of NHPD Chief James Lewis regarding the recent crackdown on prostitution.

“I saw a news article in which our police chief was talking about prostitution; he called it a quality-of-life issue. He said it blurs the line between right and wrong,” Tucker said. “I think police brutality does the same thing — it is a quality-of-life issue. When our children see police officers in the street next to people with their pants down at their ankles, they begin to fear our police. If he wants to do some house cleaning, he needs to start right in his backyard.”

People at the rally were quick to point out that it is only a small number of officers that engage in this sort of behavior.

“[The Police Executive Research Forum] found that the vast majority of officers have one or no complaints filed against them,” Garlinghouse said. “But it is the few that do that demoralize the rest of the force.”

Last November the Washington, D.C.-based police consulting firm PERF — commissioned by the city to evaluate the NHPD in the aftermath of a narcotics unit corruption scandal — issued a series of recommendations for the NHPD. These included revamping IVE and adding assistant police chiefs to improve oversight.

The court should process the lawsuit request today.