Four former senior government officials will lead an independent review of the embattled Secret Service after the disclosure of a series of breaches in presidential security, the Homeland Security Department announced Friday.

Homeland Security Secretary Jeh Johnson said the four panelists -- two who served during the Obama administration and two from the administration of former President George W. Bush -- will submit their findings and recommendations for White House security by Dec. 15.

The panelists are former Obama administration Associate Attorney General Tom Perrelli; former Deputy Attorney General Mark Filip, who served during Bush's term; Danielle Gray, a former assistant to the president for President Barack Obama; and Joe Hagin, deputy chief of staff for operations during the Bush administration.

Johnson said the panel can also make recommendations for a new Secret Service director.

Earlier this month, Julia Pierson resigned as Secret Service director, a day after testifying on Capitol Hill about an embarrassing September security breach at the White House in which a Texas Army veteran was able to climb over a White House fence and run deep into the executive mansion.

Hours after her testimony two Washington newspapers revealed for the first time that just days before the Sept. 19 White House breach, President Barack Obama had ridden an elevator in Atlanta with a security contractor armed with a gun. The Secret Service had not properly vetted the contractor.

The White House has said Obama wasn't told about the incident until shortly before details of the encounter were published.

A new director is not expected to be appointed until after an investigation into the White House breach is completed next month. In the meantime, retired Secret Service Agent Joseph Clancy will lead the agency.