Peter J. Newsham is announced as new police chief in Washington on Feb. 23. (Bonnie Jo Mount/The Washington Post)

Longtime law enforcement veteran Peter Newsham was named the District’s permanent police chief Thursday, signaling an intent by the mayor to maintain continuity amid a steady drop in crime and satisfaction over the direction of the department.

The 52-year-old Newsham, who served as interim chief after Cathy L. Lanier departed in September, faces significant challenges as he takes the helm of police force with nearly 3,800 officers and one of the highest profiles in the country. The department is working to maintain relationships it has painstakingly built in neighborhoods where trust does not come easily and to rebuild a frontline crime-fighting force depleted by a recent wave of retirements.

Newsham, whose appointment is subject to confirmation by the D.C. Council, has been on the force for nearly 28 years. He worked as an assistant chief under the two previous police chiefs — Lanier and Charles H. Ramsey — whose combined 18 years of leadership transformed a department plagued by allegations of excessive force and a city with a homicide rate nearly three times higher than it is today.

Mayor Muriel E. Bowser (D) praised Newsham’s “commitment to transparency” and his “availability to his officers and members of the public.” She added that “during uncertain times, Washingtonians know the D.C. police department is here.”

The mayor’s staff culled more than 100 applicants before settling on a final dozen, then narrowing it to four who each met several times with Bowser.

D.C. Council Chairman Phil Mendelson (D), who has supported Newsham, said, “I don’t think he’ll have difficulties” getting confirmed.

Chuck Wexler, executive director of the Police Executive Research Forum, which advises police agencies on best practices, said Newsham has been on the force “in the bad days and in the good days” and has a deep knowledge of the department.

He noted that Ramsey picked Newsham to oversee a department overhaul after concerns surfaced in the late 1990s over the high number of deadly shootings by officers. Newsham also was instrumental in helping Lanier reduce homicides when she named him chief of investigations.

“I’m sensing the mayor did not want dramatic change,” Wexler said. “The message she is sending is she wants to continue in the direction they’re going.”

Newsham takes over at a time when violent crime has generally been on the decline, although a 2015 spike in murders caused concern. Robberies also have been a persistent problem.

“One violent crime is one crime too many, especially when it happens in your neighborhood,” Newsham said after Bowser made his appointment official.

Council member Charles Allen (D-Ward 6), chairman of the council’s public safety committee, said he plans to hold three hearings before a committee vote and then a vote by the full council. “I have a lot of respect for Chief Newsham,” he said. “I hold him in high regard.”

But Newsham, whose annual salary will be $253,817 over the course of a five-year contract, could face some challenging questions. He has been criticized for mass arrests of demonstrators in Pershing Park in 2002 that sparked multimillion-dollar lawsuits against the city. Some also question arrests of protesters at last month’s presidential inauguration, alleging violations of civil rights.

Under his leadership, New­sham said, the department would work to maintain a trusting relationship with the community and stand for “unbiased, fair and constitutional policing. Everyone will know it. Not because we say it, but because we do it.”

Newsham grew up in Massachusetts, attended North Adams State College (now Massachusetts College of Liberal Arts) and earned a degree in political science from the College of the Holy Cross in Worcester, Mass. While serving with the D.C. police, he earned a law degree from the University of Maryland School of Law in 2000, and he is entitled to practice in Maryland and in the District.

He and his wife live in Southeast Washington, and he has two children in their early to mid-20s from a previous marriage. He described himself as an “unapologetic New England sports fan,” which he joked at the news conference “was easy because it was so difficult to be a Redskins fan.” After a chorus of boos from city staffers and community members, New­sham quickly saved face, saying he would make the Redskins his “NFC” team. The New England Patriots are in the rival AFC.

Newsham started as an officer at a time when a cocaine epidemic was driving violence and the city was known as the nation’s murder capital. In 1991, Newsham’s second year on the force, homicides peaked at 482. He moved through the ranks and was among its top officials when the District hit a half-century low in homicides — 88 — in 2012. The number of homicides crept up over the ensuing years and spiked 54 percent from 2014 to 2015, ending at 162. Last year concluded with 135 killings.

Under Lanier, Newsham was one of the most frequently seen police officials, appearing often on television at crime scenes, news conferences and testifying before the D.C. Council.

Bowser kept Newsham as interim chief after Lanier’s departure in September in part to avoid a distraction as the police prepared for the presidential inauguration. Newsham was intimately familiar with the process, and the official ceremonies that put the District on the world stage went off smoothly even as protesters rampaged through a four-block area of downtown, leading to more than 200 arrests.

The Jan. 20 demonstrations recalled 2002, when Newsham ordered the arrests of hundreds of anti-globalization protesters corralled by police in Pershing Park. Their advocates said the protesters were arrested without receiving a warning to disperse. Authorities last year quietly settled the final lawsuit that emerged from the incident, agreeing to pay $2.8 million to four former George Washington University students. The settlement brought the total paid to resolve the litigation to $13.25 million; the District paid $11 million of that.

Controversy over the arrests led to the revamping of police department rules over handling of protests.

Jonathan Turley, a George Washington University law professor who represented some of the Pershing Park protesters, said Newsham’s promotion to chief “sends a chilling message for civil libertarians and citizens alike” because of his “key role in one of the most abusive and costly mass arrests in the history of the District.”

Mara Verheyden-Hilliard, executive director of the Partnership for Civil Justice Fund, which also was involved in the Pershing Park cases, called Newsham “a serial mass violator of civil rights” who is “not fit to be chief of police.”

Referring to the events around President Trump’s inauguration, she said that Newsham “engaged in yet another illegal dragnet arrest.” She argued that arrestees included lawful protesters.

Newsham said Thursday that he thought at the time that his decisions at Pershing Park were “in the best interest of public safety” but had “subsequently determined that was not the right decision.”

The department, Newsham said, had “learned a great deal” from that experience and applied those lessons last month as thousands of protesters descended on downtown for President Trump’s inauguration, some with the stated goal of disrupting the event.

Police were largely hands-off even as demonstrators blocked entrances to the parade route, though more than 230 were rounded up after one group raced through an area around Franklin Square Park, breaking store windows, setting a limousine on fire and confronting police in riot gear with rocks and bricks.

This week, a grand jury indicted 214 people on charges of felony rioting, an indication Bowser said backs the decision to arrest. Newsham had stressed that most people demonstrating at the inauguration did so peacefully and that police did not interfere with them.

Newsham had made no secret that he wanted to be the District’s police chief, and in the months as interim, he acted more like a permanent leader than a caretaker. He worked closely with the police union to settle a dispute over overtime pay and reorganized a division aimed at working with groups that may feel marginalized, including the transgender community and some minority groups.

He said he would ensure that officers treat residents with respect. “When you call us, we will always come, and when we come, we are coming to help,” Newsham said.

Dan Morse contributed to this report.