[2] He was among several military officers who rebelled against the regime of President Ferdinand Marcos during the 1986 People Power Revolution.

[1] During the administration of President Corazon Aquino, he was head of the Philippine Constabulary Capital Region Command, during which he was in overall command of police officers who opened fire on protesters demanding agrarian reform during the Mendiola Massacre in January 1987, which led him to resign.

He later became chief of the Philippine Constabulary-Integrated National Police from 1988 to 1990, during which he oversaw the arrest of Reform the Armed Forces Movement leader Gringo Honasan in December 1987.

In 2006, he was arrested on charges of sedition following an alleged coup plot against President Gloria Macapagal-Arroyo but was later released due to lack of evidence.

[4] Montaño was married to Fe Pareja, who later became mayor of San Jose, Negros Oriental.