It was only an exercise, but the scenario was painfully familiar: A white police officer had just killed an unarmed Black man, and now the candidates to become New York City’s next police commissioner needed to show how they would address the media.
Some went directly into the technical details of what had occurred, Mayor-elect Eric Adams said. But one candidate began by acknowledging the loss of the victim’s life.
“That made me sit up because she understood that there was a tragedy because a life was lost,” Mr. Adams said. “That’s what we have to understand.”
The mock news conference was one test in a monthslong selection process, but Mr. Adams had found his candidate. On Wednesday, he introduced Keechant Sewell, the 49-year-old chief of detectives for the Nassau County Police Department on Long Island, as the first woman to lead the New York Police Department and its 35,000 uniformed officers.
The appointment comes amid a push to remake policing from within after last year’s protests against police brutality and systemic racism. Mr. Adams, who vowed during the campaign to choose a woman to lead the department where he was an officer for 22 years, said the way Chief Sewell handled the hypothetical situation demonstrated what he called an “emotional intelligence” that made her stand out.
“Those are the scenarios we’re going to be facing,” he said. “Hopefully we don’t have a shooting like that, but if we do, I need the police commissioner to stand in front of the room and let New Yorkers know we’re going to be all right, because it’s not only substantive, it’s the perception, right?”
Wednesday’s announcement at Community Capacity Development, an anti-violence organization in Long Island City, the Queens neighborhood where Chief Sewell was born, reflected what Mr. Adams has said will be a cultural shift for his administration, which will seek to work more with community organizations to give the public a greater role in helping the police to reduce crime.
“In this city and this moment, I have come full circle,” Chief Sewell said. “The N.Y.P.D. has an important role to play in making our communities safer, but we cannot do it alone.”
Chief Sewell is taking the helm of the Police Department at a moment of deep uncertainty.
“There’s never been a time in my 51 years in this profession that was quite as problematic as this,” said William J. Bratton, who served as police commissioner twice, most recently from 2014 to 2016. “You have the most challenging police role in the country, bar none.”
Chief Sewell is expected to play a crucial role in striking the balance that Mr. Adams wants to achieve between community-led safety strategies and traditional policing practices, including some controversial ones that Mr. Adams plans to revive, like plainclothes police units to target illegal guns. But it was unclear how much of a role she would play in steering the department from the outset: She faces a steep learning curve with just two weeks left until inauguration.
He has also charged her with diversifying a department that has made strides but is still struggling to mirror the city’s population. Although the number of Asian and Hispanic officers has risen during the de Blasio administration, the force is only about 15 percent Black, while the city’s population is roughly 25 percent Black. Female officers make up about 18 percent of the force.
Chief Sewell, who must retire as an officer and move from Long Island to New York City to take on the civilian position of commissioner, served 22 years in the Nassau County department, rising through the ranks in a variety of assignments, including narcotics and internal affairs. She was the first Black woman named chief of detectives, overseeing a division of about 350 personnel.
She was well liked among her colleagues and seen as a tough-but-fair leader of the detective bureau, said John Wighaus, the president of the Nassau County Detectives Association. In October, its members voted her Law Enforcement Person of the Year.
“She leads by example, and she has great appreciation for the men and women of our department,” Mr. Wighaus said.
The department saw her potential early on, sending her in fall 2008 to the F.B.I.’s National Academy, a prestigious and competitive training program for law-enforcement managers. She was a standout student, her counselor and classmates said, and she was elected president of the class and gave the commencement speech.
“I found her to be absolutely remarkable,” said Valerie Tanguay-Masner, who attended the academy while a member of the San Bernardino County sheriff’s office, a post from which she has since retired.
“Keechant was very athletic, very energetic, very focused and driven on what it was that she wanted to do,” she added. “I believe that her integrity is absolutely above reproach. She was a shining star.”
Art Howell, a classmate who retired earlier this year as the chief of police in Racine, Wis., said that as a Black woman and a sergeant at the time, Chief Sewell was a rare figure in the academy. Most of the other officers held higher ranks, and only 26 of the 256 attendees were women, he said.
But he said symbolism should not overshadow her qualifications. “She’s got a lot of substance,” he said.
Enormous challenges await her in New York, where relations between police and communities of color have been strained for years and calls to shrink the Police Department predate the pandemic.
Perhaps her biggest challenge will be overcoming doubts about her ability to lead a department that is vastly larger and bureaucratically more complex than Nassau County’s force of about 2,400 officers. As chief of detectives there, she has as many people under her command as the typical precinct commander in the city.
Incoming N.Y.C. Mayor Eric Adams’s New Administration
Schools Chancellor: David Banks. The longtime New York City educator, who rose to prominence after creating a network of public all-boys schools, will lead the nation’s largest public school system as it struggles to emerge from the pandemic.
Police Commissioner: Keechant Sewell. The Nassau County chief of detectives will become New York City’s first female police commissioner, taking over the nation’s largest police force amid a crisis of trust in American policing and a troubling rise in violence.
She inherits a strained relationship with the City Council and State Legislature, which her predecessors criticized for enacting laws that were aimed at making the criminal justice system fairer, but that past commissioners say scapegoated cops, emboldened criminals and made the city less safe. Gun violence, which reached a high for the decade in 2020, remains higher than before the pandemic.
On Wednesday, Chief Sewell sounded unfazed. At the news conference, she said that those who doubted her should “come and talk to me in a year.”
Dr. Tracie Keesee, who was a Denver police officer for 25 years and a deputy police commissioner in New York, said the difficulties facing the next police commissioner also present opportunities for reshaping the culture and operations of the department.
The city has already begun experimenting with having social workers respond to some mental health calls that traditionally went to police and opened an Office of Neighborhood Safety to give communities more say in how they are protected. Dr. Keesee, a co-founder of the Center for Policing Equity, a public policy nonprofit, said there’s also room to root out inefficiencies in internal processes.
Frederick Brewington, a civil rights lawyer who has sought police reform in Nassau County, said he believed that as police commissioner, Chief Sewell would be able to showcase strengths that she had not been able to display on Long Island.
Had Chief Sewell been in charge of the department, he said, he expected that the county would have seen greater progress.
“There would have been an opportunity to see meaningful reforms had she been the police commissioner in Nassau County,” he said.
Others described her as someone who impressed them with her confidence, sharp intellect and keen listening and problem-solving skills.
“There was no chink in the armor,” said Jeffrey Knotts, a retired F.B.I. special agent who was her counselor at the F.B.I. academy.
Paul Tonna, who first met Chief Sewell through a two-year leadership program he helps run at Molloy College on Long Island, said that she once led a policing demonstration for attendees alongside decorated SWAT team and K-9 unit officers — a group that Mr. Tonna noted was largely older white men.
“All of these guys with all these stars on their lapel, and Keechant absolutely commanded all of their respect,” he said. “She is the real deal and an unbelievable force of nature.”
One of the participants, Tracey Edwards, a member of Long Island Advocates for Police Accountability, said she has sought to enact reforms within the police department in Nassau County but found the department reluctant to embrace change. “But she didn’t have a place in that resistance,” Ms. Edwards said of Chief Sewell. “That to me says it all.”
Chief Sewell’s love of the city and her varied law enforcement background will be a strength as she takes on her new role, Ms. Tanguay-Masner said.
“I think that everything that has happened in Keechant’s career up until today has prepared her for this challenge,” she said.
Emma G. Fitzsimmons contributed reporting. Kitty Bennett and Jack Begg contributed research.