Can I listen to San Mateo County Sheriff on a police scanner?

No. San Mateo County Sheriff has fully encrypted their radio communications using P25 AES-256. No consumer scanner can decode encrypted transmissions.

Why did San Mateo County Sheriff encrypt their radio?

Police departments typically cite officer safety and operational security as reasons for encryption. However, encryption also eliminates public oversight, prevents journalists from monitoring police activity, and can harm emergency coordination with other agencies.

Can San Mateo County reverse the encryption decision?

Yes. Encryption is a policy choice, not a technical requirement. Multiple communities have successfully reversed encryption decisions through public pressure, city council advocacy, and coalition building. See our guide on fighting encryption for specific strategies.

What can I do about San Mateo County Sheriff encryption?

You can: 1) Contact your local elected officials to express concerns, 2) Attend city council meetings during budget discussions, 3) File FOIA requests for radio recordings, 4) Join or build a local coalition advocating for transparency, 5) Support legislation requiring public access to police communications.

Sheriff's Office Fully Encrypted

San Mateo County Sheriff

Q: Is San Mateo County Sheriff radio encrypted?

Yes. San Mateo County Sheriff uses P25 AES-256 encryption. This agency encrypts all of their radio communications, including routine dispatch. The public, journalists, and even other first responders cannot monitor their activities.

San Mateo, California

Encryption Details

Encryption Type P25 AES-256

Scope All Narcotics operations

Technical Details P25 AES-256

Verified Talkgroup Data

Verified Mar 6, 2026 Moderate confidence

36 Total Talkgroups

4 Encrypted

32 Unencrypted

11% Encrypted

Radio System: Caltrans (District 4 - South), San Francisco County/City P25, Lawrence Livermore National Laboratory, San Mateo County P25 Regional Communications System, Fisher Wireless TeamTalk, Signature Wireless Group iDAS Multitrunk (Bay Area), TelePath Corporation (Connect Plus), Silke Communications FleetNet, California Radio Interoperable System (CRIS)

View 4 talkgroups

DEC	Alpha Tag	Description	Status
1413	SFGH	San Francisco General Hospital	Encrypted
1414	SFGH BASE	San Francisco General Hospital - Base	Encrypted
1420	VA	San Francisco VA Medical Center	Encrypted
783	VA White	Valley White - Stockton (62) / Tracy (103) / Amador (94) / San Andreas (49)	Encrypted

What This Means

This agency encrypts all of their radio communications, including routine dispatch. The public, journalists, and even other first responders cannot monitor their activities.

Impact on Transparency

Journalists cannot monitor police activity for breaking news or investigative reporting
Community members cannot track police response to incidents in their neighborhood
Researchers cannot study police communication patterns and response times
Other first responders may face interoperability challenges during emergencies

San Mateo County Sheriff San Mateo, California

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California Contacts

Senator Josh Becker SB 719 Sponsor (D-San Mateo) (916) 651-4013

Assembly Public Safety Committee Key Gatekeepers (916) 319-3744

California News Publishers Association SB 719 Co-Sponsor Website

First Amendment Coalition Press freedom advocates Website

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San Mateo County Sheriff

Encryption Details

Verified Talkgroup Data

What This Means

Impact on Transparency

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