The U.S. Department of Homeland Security on Friday named four people to conduct an independent review of the Secret Service after a series of security breaches including a fence jumper who got into the White House last month.

The panel will present its review by Dec. 15, Homeland Security Secretary Jeh Johnson said in a statement.

Members of the panel are: Tom Perrelli, former associate attorney general; Mark Filip, former deputy attorney general; Danielle Gray, former assistant to the president; and Joseph Hagin, former White House Deputy Chief of Staff for Operations.

Johnson said he also asked the panel to recommend potential directors to lead the Secret Service and determine if there should be a broader review of the agency. Its latest director, Julia Pierson, resigned amid fierce criticism after the latest intrusion.

A separate, ongoing inquiry by the Secret Service into the Sept. 19 White House intrusion will be completed by Nov. 1, Johnson said in a statement.