He was a law clerk to Justice Michael J. Eagen of the Supreme Court of Pennsylvania from 1963 to 1964.
He was a judge on the Pennsylvania Court of Common Pleas, Forty-fifth Judicial District from 1978 to 1998.
Munley was nominated by President Bill Clinton on June 4, 1998, to a seat on the United States District Court for the Middle District of Pennsylvania vacated by William W. Caldwell.
[2] In 2007, Munley ruled that an ordinance punishing anyone who rents to or hires undocumented immigrants is unconstitutional.
His grandfather William J. Munley also served in the Pennsylvania General Assembly.