Fahey's departure is the latest in a string of leadership changes at the Department of Homeland Security, and he is the most recent acting ICE director to step down. Last month, Fahey's predecessor -- Tony Pham
-- departed. Pham had assumed the post last August.
Over the last four years, DHS has been encumbered by consistent turnover in leadership. This week, Chad Wolf, who served as acting Homeland Security secretary for 14 months, stepped down
amid increasing scrutiny over the validity of his appointment.
Wolf told CNN
his decision to leave office earlier than planned was due in part to the most recent court case challenging his authority to lead the department.
"As I talked with the attorneys, and we've talked with the Department of Justice and others, there was no, there was no light at the end of the tunnel, there was no avenue to really fight this," he said.
As a result, just days from a major security event, the department installed Federal Emergency Management Agency Administrator Pete Gaynor to serve as acting secretary.
ICE -- an agency under DHS -- has had six directors under President Donald Trump. The agency has never had a Senate confirmed director during the Trump administration.
Fahey, a political appointee, previously served as acting principal legal adviser at the agency, overseeing ICE's legal portfolio. He took over the acting chief post at ICE on December 31. It's unclear what prompted Fahey's departure. An ICE spokesperson said Tae Johnson, the deputy director, will serve as acting director for the time being.
In the run-up to the presidential election, the agency fielded criticism for singling out so-called sanctuary cities and signed off on putting up controversial billboards
in the key swing state of Pennsylvania about immigration violators.