After graduating with honors from West Point Academy, Paul Kellerman served in Gulf War, achieving the rank of Major. Although he had a promising future in the military, he received a better offer from the federal government: a leadership position within the Secret Service. He was eventually assigned to Vice President Caroline Reynolds, who he has served for fifteen years. Due to his commitment to her plans, he became a key figure in conspiracy that framed Lincoln Burrows for murder. Officially, as revealed in episode "The Rat", he is no longer listed as a member of the Secret Service or even as an employee of the Federal Government. Kellerman is at least 35 years old.