NEW YORK >> A New York City police sergeant was acquitted Thursday of murder in the fatal 2016 shooting of a bat-wielding, mentally ill 66-year-old woman in the bedroom of her Bronx apartment.

The death of the woman, Deborah Danner, became a flash point in the national, racially charged debate over whether police officers are too quick to shoot people and whether they are adequately trained and sufficiently conscientious in their dealings with people suffering from severe mental illness.

The sergeant, Hugh Barry, 32, had also been charged with manslaughter and criminally negligent homicide and chose to have his case decided by a judge instead of a jury; he was acquitted on all counts by Justice Robert A. Neary of state Supreme Court.

Because the sergeant claimed self-defense, Neary said that the prosecution needed to prove that he was “not justified in the use of deadly physical force.”

“The prosecution’s evidence has failed to meet that burden of proof,” he said.

Barry’s trial focused on the Police Department’s protocols for dealing with emotionally disturbed persons, or “EDPs.” Prosecutors argued that Barry escalated the encounter by not proceeding as cautiously as departmental guidelines and his training demanded.

Some critics of police said that Danner, a black woman who was shot by a white sergeant, was another casualty of a criminal justice system that values white lives over black ones.

But the sergeant’s lawyer, Andrew C. Quinn, argued that the department’s training set few hard-and-fast rules, often leaving decision-making to field supervisors, such as Barry, a nine-year veteran.

Barry remained suspended from the force with pay today. Union leaders called for his immediate reinstatement. They characterized his conduct as not only legal, but entirely reasonable.

“I think any sergeant, or officer, put in the same situation would react the same way,” said Ed Mullins, president of the sergeants’ union.

Barry shot Danner about 6:30 p.m. Oct. 18, 2016, in the bedroom of her seventh-floor apartment. From the start, he maintained he had acted in self-defense. He said Danner refused his orders to drop a baseball bat and began to swing it at him.

Police had been called by a building security guard because Danner, a paranoid schizophrenic with a history of hospitalizations, had been ranting in a hallway and tearing posters off the wall. It was the third such call in two years. The previous two times police had to break down her door to extricate her.

The shooting drew swift condemnations from Mayor Bill de Blasio and James P. O’Neill, the police commissioner, who said Barry had failed to follow protocols, though neither said he had committed a crime.

On Thursday, the Police Department left unanswered the question of whether Barry would be welcomed back into the force or disciplined. In a statement, O’Neill said the Police Department would now proceed with its own “disciplinary review of the tactical and supervisory decisions leading to the discharge of a firearm in this case.”

For many New Yorkers, the case echoed the 1984 shooting of Eleanor Bumpurs, another mentally ill woman killed by police in her Bronx apartment.

Danner, a former information-technology worker who lived alone, was well aware of Bumpurs’ fate. She cited it in a 2012 essay about her struggles with schizophrenia.

“They used deadly force to subdue her because they were not trained sufficiently in how to engage the mentally ill in crisis,” she wrote. “This was not an isolated incident.”

Since the Bumpurs killing, officers have been trained to isolate and contain emotionally disturbed people, taking time and continuing to talk to them to persuade them to comply.

But the trial underscored the distinction between questionable tactics and criminal conduct that has made convictions of police officers rare even in killings where they deviate from protocol.

At the three-week trial, prosecutors argued that Barry had rushed to subdue Danner, forcing the fatal confrontation. They faulted him for not learning details of two recent encounters Danner had had with police, despite riding the elevator to Danner’s floor with her sister. And once he entered the apartment, prosecutors said, he could have called for help from a police unit specializing in dealing with the mentally ill.

A prosecutor, Wanda Perez-Maldonado, said in her closing arguments that Danner was shot in the “safe place” of her own bedroom.

But Quinn, the sergeant’s lawyer, argued that it was far from clear what Barry should have done. If he had shut the bedroom door to isolate Danner, she might have stabbed herself with the scissors — in which case he might have been blamed for not intervening more resolutely, Quinn said.

Barry, who testified in his own defense, said that when he arrived and learned from another officer that Danner was in her bedroom with scissors and refused to come out, he started talking to her, coaxing her to speak to emergency medical technicians.

After a few minutes, he said, she slammed the scissors down on a nightstand and came just outside her bedroom door.

Barry said he figured Danner would not come any farther. He decided to grab her before she could return to the bedroom and grab the scissors again. He nodded to the other officers and rushed her.

But Danner retreated to the bedroom, jumped on the bed, and pulled a baseball bat from the bedclothes. Barry ordered her to drop it. She stood up in a batter’s stance and moved her foot toward him to start a swing. He fired twice into her torso.

“I just see the bat swinging and that’s when I fired,” he testified.

He said he could not back up because his colleagues were crowded close behind him.

The only other officer with a clear view, Camilo Rosario, said the bullets hit Danner before she swung the bat, though he added that he believed she was about to swing.

Barry’s account differed in many small but significant ways from those of some of the five other officers and two medics who were present. Rosario, for instance, recalled that it was he who persuaded Danner to put down her scissors and come to the bedroom door.

Throughout the trial, members of the Sergeants Benevolent Association union sat in the front row in a show of support. Several said they thought the prosecution was politically motivated.

Members of the Episcopal churches Danner attended, her sister, and Black Lives Matter activists also filled the benches. As Neary delivered his verdict, they sat with their hands at their mouths and closed their eyes.

The judge offered no detailed explanation.

Some of Danner’s supporters criticized the verdict.

“Racism is still alive and kicking and anyone who tells you different is lying,” said Wallace Cooke Jr., a former city police officer whose cousin is Danner’s mother. Hawk Newsome, a Black Lives Matter activist, said the verdict felt “like somebody just ripped my heart out.”

Barry’s supporters were jubilant. Officers hugged and clasped hands. Some wiped away tears.

Another Black Lives Matter activist, Joshua Lopez, 39, called after the president of the Patrolmen’s Benevolent Association, Patrick Lynch, “What if that was your mother?”

Matthew Heyd, a priest at the Church of the Heavenly Rest in Manhattan, recalled Danner as “always in church,” and a frequent participant in knitting circles and discussion groups. “She always asked the tough questions,” he said.

In her own essay, Danner described schizophrenia as “a curse” that led to “a complete loss of control.”

Her illness, she wrote, had cost her jobs and family ties. She described roaming through the streets with a knife in search of a public place to kill herself. When she was well, she wrote, she was constantly examining herself for signs of a relapse.

“Generally speaking, those who don’t suffer believe the worst of those of us who do,” she wrote. “We’re asked to accept less than our natural rights to life, liberty and the pursuit of happiness.”