David Hay, deputy chief of staff to schools chancellor Richard Carranza, was fired after his arrest, officials said.

David A. Hay

A high-ranking official in New York City’s Department of Education was arrested on Sunday in Wisconsin and accused of using a computer to facilitate a child sex crime, according to police officials there. 

David A. Hay, the deputy chief of staff to schools chancellor Richard A. Carranza, was taken into custody at an airport in Milwaukee following an ongoing undercover investigation, said Officer Stuart Zuehls, a spokesman for the Neenah, Wis., police department.

Authorities in Wisconsin notified New York City officials hours after the arrest on Sunday. The Department of Education said it fired Mr. Hay after the arrest. 

“These allegations are incredibly disturbing and absolutely unacceptable,” Miranda Barbot, a spokeswoman for the department, said in a statement. “We took immediate action removing Mr. Hay from payroll and are terminating him. We referred this to the Special Commissioner of Investigation and we will fully comply with any investigation.”

David A. Hay

The special commissioner, Anastasia Coleman, confirmed that the agency was looking into the matter. 

Mr. Hay, 39, did not regularly interact with students as part of his job, which was based at department headquarters in downtown Manhattan. Before moving to New York, however, he was a school principal in two Wisconsin school districts. 

Mr. Hay took a leave of absence from his job as a high school principal in the Kettle Moraine School District in suburban Milwaukee in late 2010, and left that job in early 2011, citing differences with the district’s superintendent, according to the Milwaukee Journal Sentinel.

“It is not clear whether a completed background investigation would have revealed information relevant to the current charge against Mr. Hay,” said Margaret Garnett, the Department of Investigation commissioner. 

Ms. Garnett said she inherited a massive backlog of 6,000 unfinished background checks when she took control of the department in January, some dating as far back as 2015. “The risks presented by this example are exactly why I took immediate steps to assess and then reorganize the Background Investigation Unit,” she said, referring to Mr. Hay.

The scope of the problem is still unclear, though the unfinished background checks apply to high-ranking officials and policymakers across Mayor Bill de Blasio’s administration. Ms. Garnett said she had taken immediate action to begin to address the issue. 

Officer Zuehls, of Neenah, declined to offer more information about the specific charges or why Mr. Hay was arrested at an airport.

Wisconsin state law indicates that someone accused of using a computer to facilitate a child sex crime is suspected of attempting to sexually abuse a child. The law defines that charge as a person who “uses a computerized communication system to communicate with an individual who the actor believes or has reason to believe has not attained the age of 16 years with intent to have sexual contact or sexual intercourse with the individual.”

It is not yet clear when the investigation into Mr. Hay was launched, or whether Mr. Hay has obtained a lawyer. 

The investigation was conducted by the Neenah police department, with help from the Milwaukee County Sheriff’s Department, though it is not yet clear what precise role the Milwaukee police played. 

The investigation is ongoing, and there is no information yet about when Mr. Hay will be arraigned. 

Mr. Hay grew up in the small town of Antigo, Wis., about three hours from Milwaukee, according to a 2017 interview.

Mr. Hay has served under both of Mr. de Blasio’s schools chancellors: Mr. Carranza, who was appointed in the spring of 2018, and former chancellor Carmen Fariña.

He rose quickly in the Department of Education after joining in May 2016, first serving as a special assistant to Ms. Fariña while he was still a student at the Harvard Graduate School of Education, then helping oversee major programs — including the Renewal School initiative to help struggling schools — before being promoted to a deputy chief of staff last October, according to his page on LinkedIn.

He maintains an active Twitter account where he promotes Department of Education events and positive news stories about the department. 

He spoke about his work at the Department of Education in a 2017 news item for the Harvard Graduate School of Education School’s website.

“To jump to the largest school system on the planet is incredible,” he said. “It’s humbling, challenging, and really promising.”