Edward Caban, the New York Police Department’s first deputy commissioner and an ally of Mayor Eric Adams, will become the interim head of the agency, the mayor said Friday.

“There’s a natural process in place that the first deputy commissioner falls in line until we make a permanent announcement on who the commissioner is going to be,” Mr. Adams said during a radio appearance on 1010 WINS. “And we are going to find a suitable replacement.”

The announcement coincided with the last day in office of Keechant L. Sewell, the department’s first Black and first female commissioner, who abruptly announced her resignation two weeks ago, after finding that her powers had been circumscribed by the mayor and his allies.

Her departure is one of a wave of high-level officials exiting the still-young administration. The mayor has also lost or is losing his chief housing officer, Jessica Katz, in the midst of a housing crisis; his social services commissioner, Gary Jenkins, in the midst of a record-setting homelessness crisis; his chief counsel, his communications director, his chief efficiency officer, his buildings commissioner and his chief of staff.

Mr. Caban will head the department of 36,000 uniformed officers and 19,000 civilian employees as the mayor conducts a national search for a permanent successor to Ms. Sewell. A spokesman for the mayor declined to detail the criteria that are guiding the mayor’s search. But Mr. Adams, a former police captain, is known to have strong feelings about policing and about the close management of his departments.

He likes to repeat an adage he says he learned from his mother: “If you don’t inspect what you expect, it’s all suspect.”

“Now some people may call that a micromanager,” he said after Ms. Sewell resigned. “I call it being the mayor of a city that you love.”

Mr. Caban, a father of two young children whose own father was a New York City Transit Police Department detective, began his career in the Bronx in 1991. He was handpicked for the department’s second-highest job not by Ms. Sewell, but by Mr. Adams, according to several current and former officials.

His record is not unblemished. In 1997, the Civilian Complaint Review Board, a city oversight agency, recommended that he be disciplined after two officers were accused of cursing and threatening a woman in front of her young son in Harlem. Mr. Caban, then a sergeant, “abused his authority,” according to the board, when he refused to give the woman their names.

Still, he rose through the ranks. In 2005, he was promoted to captain and in 2006 was made commander of the 25th Precinct, according to the department.

That same year, the board found again that he had abused his authority as a captain when he had stopped a man on a Manhattan street while investigating robberies. When the man refused to provide identification, Mr. Caban arrested him for disorderly conduct. The man was later released.