In February 1897, he joined his brother, Emilio, who was defending the town of Dasmariñas, Cavite, from the troops of General Lachambre of the division of Captain-General Camilo Polavieja.

Críspulo attended the Tejeros Assembly on March 22, 1897, in San Francisco de Malabon (now General Trias), where his brother Emilio was voted as the president of the reorganized revolutionary government.

Colonel Vicente Riego de Dios was sent by the assembly to fetch General Emilio Aguinaldo who was then in Pasong Santol.

He greeted his brother and explained his purpose, but Emilio was hesitant to leave because of the pending attack of the Spanish forces in Dasmariñas and Imus.

Críspulo didn't want to return to Tejeros without his brother, so he volunteered himself to stay behind in the area and promised that no Spaniard will take over Pasong Santol; that they would only take it over his dead body.