Casimiro Castillo is a municipality, in Jalisco in central-western Mexico. The municipality covers an area of 522.7 km². As of 2005, the municiā¦Casimiro Castillo is a municipality, in Jalisco in central-western Mexico. The municipality covers an area of 522.7 km². As of 2005, the municipality had a total population of 18,913. Five police officers from Casimiro Castillo were arrested for the murder of a young man on August 26, 2020. The body of Alfredo Sevilla, mayor on leave, was found at the bottom of a gully on March 10, 2021.