Top image (representative): A U.S. post office and mail collection box in Champion, Mich. Photo: Tony Webster / CC BY 2.0 via Wikimedia Commons

Less than three weeks before the Nov. 3 election, San Mateo County election officials are asking voters to check that their ballots arrived, after a theft at a Daly City post office that may have included vote-by-mail ballots.

On Oct. 14, the Registration and Elections Division of the San Mateo County Assessor-County Clerk-Recorder’s Office was notified of a mail theft at a Daly City post office, and the stolen mail “reportedly included” county ballots, the office said in an Oct. 15 release. The number of ballots potentially affected has not been determined. The U.S. Postal Inspection Service is investigating.

What is known, and what isn’t

An employee at the Daly City postal location reported the theft at 4:30 p.m. Wednesday, KRON4 reported, citing county officials, who added that it had not been confirmed that any ballots were taken. The U.S. Postal Service told ABC7 that mail was taken from the loading dock of the post office on Sullivan Avenue. Officials told the station they do not believe the thieves went after the mail because it contained ballots. The Daly City Police Department told ABC7 it has no open case because the theft was reported internally to postal investigators.

Assistant Chief Elections Officer Jim Irizarry told the San Mateo Daily Journal there did not appear to be a reason to assume it was an attempt to tamper with voting, KQED reported. “Unfortunately, mail theft does occur. From our perspective, voting by mail is very safe, and it is very convenient,” Irizarry told ABC7.

The county’s main reassurance is in how ballots are processed. “Each Vote-by-Mail ballot is associated with an individual voter, and ballot processing safeguards prevent duplicate ballots from being counted for the same voter,” the division said in a statement quoted by KQED. In other words, a stolen ballot cannot be cast on top of a legitimate one; at worst, a voter whose ballot disappeared would have to vote again.

What voters can do

Voters can track their ballots through the Secretary of State’s free “Where’s My Ballot” service, which shows when a ballot is mailed, received and processed, the San Francisco Chronicle reported. Anyone concerned can request a replacement online by Oct. 27, or in person at any San Mateo County Vote Center, according to the county.

The county’s release also spells out the return deadlines: ballots dropped in an official county drop box must be in by 8 p.m. on Election Day, and mailed ballots must be postmarked by Election Day and received by Nov. 10. Officials advise voters mailing close to the deadline to hand their ballot to a postal clerk and ask for a hand postmark.

Context matters

It isn’t the first time this year that ballots have shown up in a South Bay mail theft. In June, a little over two dozen Santa Clara County ballots were found among recovered stolen mail, and federal investigators said the thieves did not appear to be targeting election mail, KQED reported. The station also cited a 2025 Brookings study finding that mail voting fraud is “very rare,” about four cases per 10 million mail-in votes.

The politics will last longer than the investigation. San Mateo County Supervisor David Canepa, who ABC7 reported will take over as the county’s chief elections officer in January, said he plans to look at how to prevent similar incidents. “What we need to do is to make sure that people understand that there are consequences for taking mail, and there are consequences for taking ballots,” he said.

The long view

California has built its elections around the mail, and the system’s defense against theft is no longer only physical security. It is data: barcoded envelopes tied to individual voters, signature checks, statewide tracking and a rule that only the first accepted ballot counts. Those systems are designed to make a theft like this an inconvenience for a few voters rather than a threat to the result.

The vulnerability is trust, not math. A ballot on a loading dock is also a story that can travel much farther than the facts. The most useful thing officials can do in the next two weeks is be specific: say how many ballots were in the stolen mail once postal inspectors know, how many replacements were requested, and whether any stolen ballot ever reached the county. Whether the tracking system really works is only half the test; the other half is whether people believe it does.

That matters on this ballot, which includes the regional transit measure and the North County supervisor race. (See our coverage of Measure RTM and the District 5 race.)

Sources: San Mateo County Assessor-County Clerk-Recorder & Elections (Oct. 15, 2026); KQED (Oct. 16, 2026); San Francisco Chronicle (Oct. 16, 2026); ABC7; KRON4.