He graduated from George Washington University's National Law Center in 1986 cum laude.

NASA Inspector General Cobb worked for five years as an associate at the law firm of Ober, Kaler, Grimes & Shriver.

Cobb worked for almost nine years at the United States Office of Government Ethics before becoming Associate Counsel to the President in the George W. Bush administration.

In this position he was responsible for the administration of the White House ethics program (the conflict of interest and financial disclosure clearance for candidates for nomination to Senate-confirmed positions) under the supervision of then-White House Counsel Alberto Gonzales.

President George W. Bush appointed Cobb to the position of NASA Inspector General on February 25, 2002.