Graduate of Philippine Military Academy class of 1966, Sarmiento served as commander of Special Action Force from June 6, 1992, until January 2, 1994,[1] and National Capital Region Command.

[3] This move was seen by some as a challenge to the established seniority hierarchy within the PNP.

Despite facing criticism and accusations of failed leadership from columnists, Sarmiento completed his term as PNP Chief, which lasted until December 15, 1997.

[4] Sarmiento supported Ping Lacson's presidential campaigns, first in 2004,[5] and also in 2022.

In 2004, he served as provincial chairman of Ping Lacson for President Movement in Quezon.