He took his elementary and high school studies at De La Salle University, and then on his father's insistence, entered the Philippine Military Academy (PMA) in 1963.

Timing the raid when most cadets were out on Christmas vacation and the PMA's senior officers including its Superintendent, General Ugalde had left the camp to meet President Ferdinand Marcos upon his scheduled arrival in nearby Baguio.

[9] Corpus, who was PMA's designated officer of the day (OOD), guided the NPA raiding team which managed to escape with Browning automatic rifles, carbines, machine guns, and various other weapons and ammunition.

[11] Disgruntled with the Communist Party of the Philippines, Corpus decided to surrender to government in July 14, 1976,[8][9] due to disillusionment over the organization citing the 1971 Plaza Miranda bombing which the NPA is alleged to have a role in committing.

During the God Save the Queen Plot against President Corazon Aquino in November 1986, the Reform the Armed Forces Movement's chief propagandist, Captain Rex Robles, leaked to the media a letter from Corpus, in which he claimed to have witnessed the CPP leadership planning the Plaza Miranda bombing in 1971, which prompted him to surrender to the government.