The new Homeland Security secretary's choice to be his chief of staff was once a key player in the downfall of a Pennsylvania state senator on corruption charges.

Chief of staff Christian Marrone was a prosecution witness against his father-in-law, Vince Fumo, during Fumo's 2008 federal corruption trial. Fumo was convicted of several charges and served more than five years in federal prison.

Marrone, a lawyer who went to work for Fumo shortly after graduating from college, took the stand against his former boss several years after leaving Fumo's office.

The Homeland Security Department says Marrone will be a strong addition to its leadership.

Marrone's appointment to Secretary Jeh Johnson's inner circle and the details about his ties to Fumo was first reported by The Washington Times.