In November 2025, the County of San Mateo amended its Non-Cooperation with Immigration Authorities ordinance. This amended ordinance strengthened the county’s commitment to upholding policies that provide protection to all residents regardless of immigration status. 

As part of this new ordinance, the Probation Department will be publishing data on a quarterly basis on the number of immigration detainer requests and warrants received from immigration authorities.

This data also strengthens the Probation Department’s commitment to maintaining public safety and public trust and ensuring transparency within San Mateo County, particularly among immigrant communities.