Thomas Donlon, a Bronx native who has an extensive background in federal law enforcement, will become New York City’s interim police commissioner following the resignation of Edward A. Caban on Thursday.

Most recently, Mr. Donlon ran his own private security and consulting company called Global Security Resolutions, which he founded in 2020.

Mayor Eric Adams, in announcing his appointment at a news conference, called Mr. Donlon “an experienced law enforcement professional who has worked at the local, state, federal and international levels.”

Among his many positions, Mr. Donlon was the director of the state homeland security office in New York, has worked for the F.B.I. and served in counterterrorism roles domestically and abroad and in security for Wall Street firms.

Here is what to know about Mr. Donlon and his background:

Adams oversaw a key confirmation

Mr. Adams and Mr. Donlon have known of one another since at least early 2009, when Mr. Adams, then a state senator, became the chair of the Senate’s Veterans, Homeland Security and Military Affairs Committee.

In February 2009, according to a news release that Mr. Adams’s office issued at the time, that committee confirmed Mr. Donlon’s nomination to head New York’s Office of Homeland Security.