Special Notice / Hearing: None__
Vote Required: Majority
To: Honorable Board of Supervisors
From: Ken Binder, Sheriff’s Office
Subject: Sheriff’s Office Compliance Report - pursuant to Chapter 2.48 of Title 2 of the San Mateo County Ordinance Code
RECOMMENDATION:
title
Accept the Sheriff’s Office Report on interactions with Immigration Authorities, pursuant to Chapter 2.48 of Title 2 of the San Mateo County Ordinance Code.
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BACKGROUND:
On December 2, 2025, the San Mateo County Board of Supervisors adopted an ordinance amending Chapter 2.48 of Title 2 of the San Mateo County Ordinance Code that requires the Sheriff’s Office to provide a written report on known immigration activities within the Sheriff's Office jurisdiction, including civil immigration detainer requests as well as any communications related to immigration authorities by March 1, June 1, September 1 and December 1 of each year.
DISCUSSION:
The Sheriff’s Office is committed to maintaining public safety and public trust and ensuring transparency within San Mateo County, particularly among immigrant communities.
DEFINITIONS:
An Immigration Detainer is a request from the U.S. Immigration and Customs Enforcement (ICE) to a local jail or police department.
What it is:
A notice saying: “If you’re about to release this person, please hold them for up to 48 extra hours so ICE can come pick them up.”
Important:
• It is NOT signed by a Judge.
• It IS an administrative request from a federal immigration agency.
• The San Mateo County Sheriff’s Office does NOT act on Immigration Detainers, pursuant to the California Values Act (SB 54) and County ordinance.
A Judicial Warrant is an official order signed by a Judge.
What it is:
A Judge reviews evidence and formally orders law enforcement to act upon something specific including:
• To arrest someone
• To take someone into custody
Judicial Booking is:
Taking custody of the person who has been arrested and processing them within the correctional system.
Important:
• The San Mateo County Sheriff’s Office IS required by law to act upon Judicial Warrants and Judicial Bookings.
The table below represents the number of requests the Sheriff’s Office has received from immigration authorities since January 2025. Note: not all data was collected prior to March 2025.
|
Date |
Year |
Immigration Detainers Received |
Number of Detainers Acted Upon |
Judicial Warrants or Judicial Bookings Received |
Judicial Warrants or Judicial Bookings Acted Upon |
|
|
|
|
|
|
|
|
January |
2025 |
* |
0 |
0 |
0 |
|
February |
2025 |
* |
0 |
0 |
0 |
|
March |
2025 |
70 |
0 |
0 |
0 |
|
April |
2025 |
82 |
0 |
0 |
0 |
|
May |
2025 |
107 |
0 |
0 |
0 |
|
June |
2025 |
111 |
0 |
1 |
1 |
|
July |
2025 |
132 |
0 |
0 |
0 |
|
August |
2025 |
91 |
0 |
0 |
0 |
|
September |
2025 |
112 |
0 |
0 |
0 |
|
October |
2025 |
106 |
0 |
0 |
0 |
|
November |
2025 |
67 |
0 |
0 |
0 |
|
December |
2025 |
91 |
0 |
0 |
0 |
|
January |
2026 |
70 |
0 |
0 |
0 |
|
February |
2026 |
42 |
0 |
1 |
1 |
|
Totals |
|
1081 |
0 |
2 |
2 |
* Information was not collected prior to March 2025
Note: The "Judicial Warrants or Judicial Bookings Received" column may include data for arrests made by other agencies in other jurisdictions but were later booked into San Mateo County correctional facilities.
In June 2025, the Sheriff’s Office received a Federal Judicial Warrant for the arrest of a person already in Sheriff's Office custody at a San Mateo County correctional facility. The Federal Judicial Warrant was added to the person's case.
In February 2026, the San Mateo County Sheriff’s Office took custody of a person in Riverside County pursuant to a San Mateo County criminal case. Upon taking custody of the arrestee, the Sheriff’s Office learned that an additional Judicial Warrant had been issued by a Federal Judge and was required to be acted upon. The arrestee was subsequently booked into the Maguire Correctional Facility for the local criminal case and the Federal Judicial Warrant.
Immigration Actions
The Sheriff’s Office is not aware of any immigration actions in San Mateo County undertaken by Immigration Authorities within the County during this reporting period (Jan. 1, 2026 through March 1, 2026).
Note: Over the last few years, the Sheriff’s Office has not been notified by federal immigration agencies of immigration operations in the Sheriff’s Office jurisdiction.
COMMUNITY IMPACT:
The Sheriff’s Office operates the County’s two adult correctional facilities, the Maguire Correctional Facility and the Maple Street Correctional Center.
The Sheriff’s Office serves adults who are impacted by the justice system - regardless of their immigration status.
Through this quarterly report, the Sheriff’s Office demonstrates its commitment to upholding state law and County ordinances, which ensure equitable service to incarcerated persons in San Mateo County.
FISCAL IMPACT:
There is no fiscal impact related to this report.