By Pete Williams and Chuck Todd, NBC News
Senior administration officials confirm that President Barack Obama has chosen former Defense Department general counsel Jeh Johnson to succeed Janet Napolitano as Homeland Security Secretary.
Obama is expected to formally nominate Johnson for the position on Friday. If confirmed, Johnson, 56, would become the first African-American to lead DHS.
As the Pentagon's top lawyer from 2009 until last year, Johnson was at the center of many of the Obama administration's major decisions on issues like counterterrorism, the use of drones, and the repeal of Don't Ask Don't Tell policy.
He co-authored a report that helped pave the way for repeal of the ban on gays serving openly in the military.
He also won headlines in 2012 for a speech at Oxford University for describing a future "tipping point" at which al Qaeda would be so weakened that it would be unable to mount an attack on the United States and would be "effectively destroyed."
During the Clinton Administration, Johnson served as the general counsel of the Department of the Air Force from 1998 to 2001. Previously, he has also served an Assistant United States Attorney in the Southern District of New York.
He left the Pentagon last year to return to New York law firm Paul Weiss. In his role there, he has represented Citigroup and Gillette, among other major companies, according to the firm's web site.
Napolitano stepped down in early September to lead the University of California system. The department has been without a leader for six weeks, prompting many to call for a swift nomination and confirmation of a new secretary.
The selection was first reported by the Daily Beast.
NBC's Carrie Dann contributed.