Immigration Detainers and Warrants
The County of San Mateo has an ordinance prohibiting cooperation with immigration authorities. The Sheriff’s Office follows the County ordinance and state law, and will not hold, detain, house, transfer, or otherwise facilitate the arrest of any person unless pursuant to a judicial warrant or otherwise required by federal or state statute, regulation, or court decision.
In compliance with the County ordinance, the Sheriff’s Office will publish quarterly reports on this website detailing the number of immigration detainer requests and warrants received from immigration authorities beginning Jan. 1, 2026.
| Month *2025 | Immigration Detainers and Warrants Received | Number of Detainers or Warrants Acted Upon | Judicial Warrant Bookings*** |
|---|---|---|---|
| January | * | 0 | 0 |
| February | * | 0 | 0 |
| March | 70 | 0 | 0 |
| April | 82 | 0 | 0 |
| May | 107 | 0 | 0 |
| June | 112 | 0 | 1 |
| July | 132 | 0 | 0 |
| August | 91 | 0 | 0 |
| September | 112 | 0 | 0 |
| October | 106 | 0 | 0 |
| November | 67 | 0 | 0 |
| December | 91 | 0 | 0 |
| Totals | 970 | 0 | 1 |
* Information was not collected prior to March 2025.
** Still being counted
*** This is a warrant for the arrest of a person signed by a state or federal judge (not an immigration judge) and legally required to be acted upon
