In a statement Wednesday night, Walsh said he appointed Superintendent-in-Chief Gregory Long to serve as acting commissioner while the city hires an outside lawyer “to conduct a full and impartial investigation” into allegations that White pushed and threatened to shoot his then-wife, also a Boston police officer, and was later ordered to stay away from his family.

“These disturbing issues were not known to me or my staff, but should have been at the forefront,” said Walsh, who was in Washington, D.C., for his Thursday nomination hearing to become President Biden’s labor secretary. “Upon learning of these serious allegations, I immediately acted.”

The Globe first pressed the Police Department last week about White’s work history, including three internal affairs cases, just hours after Walsh announced he would name him commissioner. White had served as Gross’s chief of staff. The department provided some basic information, but declined to provide internal affairs cases.

The Walsh administration responded Wednesday after a Globe reporter presented the city with the domestic violence allegations that were outlined in court documents.

A judge issued a restraining order on May 5, 1999, that forced White to vacate his home, stay away from his wife and children, and surrender his service weapon. The Globe could not find evidence that White was charged with a crime. At the time, he denied the allegations in court filings.

White’s wife accused him of pushing her and hitting her once, according to court records. A friend of the couple also told police that White — after a confrontation with his wife and another acquaintance — said he “wanted to shoot her and him,” according to a summary of an interview by a Boston police detective that was included in a probate and family court file.

White’s daughter, who was then 17, recounted to the detective that her father had told her not to startle him when he was sleeping because “I sleep with a gun under my pillow.”

White’s abrupt suspension raises a number of questions about what vetting, if any, was done before Walsh last Thursday appointed White to one of the city’s most prominent positions. One of those internal affairs cases requested by the Globe coincided with the time frame of the domestic violence accusation, though it could not be confirmed that they were connected.

In his statement, Walsh said he asked White “to quickly step into the role of Police Commissioner” last Friday so Gross could spend more time with his family. Walsh made the move in what will likely be the waning days of his administration, shortly before he is set to undergo questioning in the Senate confirmation hearing.

Though Boston mayors possess the sole authority to appoint the police commissioner, the city has often taken its time, conducting national searches, naming finalists, and making efforts to involve the public, which some criminal justice experts say has become increasingly vital at a moment when trust between police and the people they serve has frayed.

City Council President Kim Janey, who will become acting mayor when Walsh leaves office, said in a statement she took “any allegation of this nature very seriously.”

“I have had the opportunity to work with Commissioner White while on the Council, but this is the first I am hearing of this issue, and I am deeply concerned,” Janey said in a statement issued before Walsh said he was suspending White. “The public deserves transparency.”

A Globe investigation published in December found Boston police officers accused of crimes over the last decade have often encountered a more forgiving justice system than the one faced by civilians. Allegations were sometimes investigated in-house and not shared with prosecutors.

The department’s current domestic violence policy notes that “arrest is the preferred response.”

Suffolk County District Attorney Rachael Rollins said in a statement that her office was not aware of the allegations against White and could not comment on them.

At White’s swearing-in ceremony this week, Walsh spoke of the department’s commitment to “accountability and transparency.” But the process of appointing White commissioner was strikingly opaque.

Under state law, Boston police commissioners serve five-year terms, though it was not immediately clear whether White would have served for a full five years or filled the remaining tenure of Gross, who was appointed in 2018.

White has a long history of public service, working first as a firefighter before joining the police force. The department once described him as a “respected street cop who has spent his career policing the neighborhoods where he grew up — Roxbury and Dorchester.” He graduated from Jeremiah E. Burke High School and as a police officer earned a 2005 bachelor’s degree in legal studies with a concentration in criminal justice from Newbury College.

In 1999, White was a sergeant and had been married to a fellow Boston police officer for nearly 20 years. In May of that year, White’s wife at the time wrote in the application for the restraining order that, “we argue a lot and he is always trying to push me down and I am afraid that he may come inside and kill me because he is angry.” The Globe is not identifying the woman because she was the potential victim of domestic violence. Reached by phone, she declined to comment.

In a subsequent divorce filing in September 2000, an attorney representing White’s wife wrote: “The Husband has admitted to hitting the Wife (once) and sleeping with a gun under his pillow.” An attorney for the future commissioner wrote that his client “adamantly denies ever striking the Wife [or] threatening to cause her harm.”

However, White’s attorney also wrote that, “the Husband concedes that there were incidents of fighting between the Parties and that on some occasions, they escalated to some physical contact by both Parties, including the Wife.” But White’s attorney argued that the restraining order and abuse allegations were an attempt to alienate White from his home and children and “humiliate him personally and professionally.”

White noted in his legal filings that his wife’s claims were contradictory. She alleged in a divorce filing that he hit her once, but a police report dated May 4, 1999, about the threat to shoot her noted that she told police they “had arguments in the past, but no physical abuse.”

The same day, a separate police report was filed against his wife for harassment because she allegedly called the Roxbury police station looking for White and yelled at the officer who answered the phone, according to records included in their divorce file.

Boston has often been content to hire its police commissioner from within its own ranks, said Chuck Wexler, executive director of the Police Executive Research Forum, an organization that aids cities in their search for new leadership.

Both of its previous commissioners — Gross and William Evans — had spent their entire careers in the Police Department. And despite the natural attractiveness of the job to national candidates, city officials have rarely plucked from outside city limits.

“For the most part, Boston is the kind of place where the mayor knows who he or she wants, picks them, and that’s it,” said Wexler, who once served as operations assistant to the commissioner in the Boston Police Department. “Some cities, that’s just what they do.”

But even in those cases, attempts have often been made to gather a wide swath of candidates.

In 1985, then-Mayor Raymond Flynn traveled to Philadelphia and New York to interview candidates for the commissioner job before ultimately deciding on his friend, Francis Roache, a longtime Boston cop.

And in 2006, then-Mayor Thomas M. Menino hired Edward F. Davis from the Lowell Police Department only after a nationwide search that included interviews with a half-dozen candidates.

Last week after his appointment, White pledged in a brief interview that he would work “to make sure we are very transparent so the public has confidence in us.”

“There won’t be any major changes at this moment,” he said. “The main thing is to just get in the door and make sure the ship is running straight. I think the department is moving in a great direction going forward.”

Andrew Ryan can be reached at andrew.ryan@globe.com Follow him on Twitter @globeandrewryan. Dugan Arnett can be reached at dugan.arnett@globe.com.