San Mateo County’s deputy sheriffs’ union is asking California’s public labor board to file a complaint against the county and the sheriff’s office, alleging multiple violations of state labor laws.

In a filing to the California Public Employment Relations Board on May 2, the San Mateo County Deputy Sheriffs’ Association claims county officials unilaterally altered internal affairs procedures, hired more correctional officers than previously agreed to, and interfered with the union president’s ability to represent members by banning him from sheriff’s office work spaces.

The union is asking the state board to issue a cease-and-desist order, require a public notice acknowledging the alleged violations, award attorney’s fees, and apply any other remedies allowed under the Meyers-Milias-Brown Act, the state law governing collective bargaining for local government employees.

Sheriff Christina Corpus has been at odds with two county sheriff unions ever since they began raising concerns about alleged corruption, workplace misconduct, and other accusations within the sheriff’s office. Since then, the relationship between the sheriff and the unions have further deteriorated amid multiple investigations and legal claims.

Corpus, the county’s first Latina sheriff, has faced mounting criticism since the release of a 400-page report authored by retired Judge LaDoris Cordell detailing allegations of misconduct, corruption, and nepotism within her administration. She is now subject to a potential removal hearing, made possible by a special election in March in which voters granted the San Mateo County Board of Supervisors the authority to remove an elected sheriff for misconduct or neglect of duty.

Despite mounting calls for her resignation, Corpus has refused to step down.

In their filing, the association alleges Corpus made staffing decisions without feedback from the union. The union pointed to the sheriff’s office exceeding an agreed cap of 164 correctional officer positions, instead employing 172 as of March.

The union contends the sheriff’s office made that decision unilaterally, without consulting them, allegedly violating bargaining rules. The San Mateo County Deputy Sheriffs’ Association, which represents both deputies and correctional officers, says the shift may reduce positions in other represented classifications and directly impacts working conditions.

Another core dispute concerns how the sheriff’s office notifies employees of internal affairs investigations.

The union says the office broke from its past practice of specifying which department policies an employee is alleged to have violated in a “Notice of Interview.”

That procedure, the union says, was not followed in the case of union president Carlos Tapia, who was arrested in November 2024 for alleged timecard fraud. In December 2024, San Mateo County District Attorney Stephen Wagstaffe declined to file charges.

According to an affidavit dated May 2, Tapia received a notice on Feb. 3, 2025, with no specific policy violations. He was later interviewed on March 14 by an internal investigator. Tapia’s attorney objected to the lack of detail provided about alleged infractions, but the interview proceeded “under threat of discipline,” the union wrote in its complaint.

“Nowhere in the notice does it list the specific San Mateo County Sheriff’s Office policies I could have potentially violated per the past practice of the department,” Tapia said in his sworn statement.

Tapia was also barred from sheriff’s office worksites the same day as his arrest in November. The order required him to stay home during work hours and prohibited him from entering any department facilities.

The association argues that both the change in internal affairs procedures and the workplace restrictions on Tapia constitute unlawful changes to working conditions.

“The evidence demonstrates that, even under a microscope, Sheriff Corpus continues to ignore basic labor law. It’s a disturbing pattern of behavior that illustrates the long-term damage she is inflicting every day she remains in office,” Deputy Sheriffs’ Association board secretary Eliot Storch said in a statement.

Corpus did not respond to a request for comment on these allegations.

The embattled sheriff has pushed back against calls to resign by filing a lawsuit against the county seeking the release of expenses related to the Cordell report.

She tapped retired Riverside County Superior Court Judge Burke E. Strunsky to conduct an independent review of the report, which helped trigger the push for her removal. In his findings, Strunsky criticized the investigation for relying heavily on anonymous sources and unrecorded interviews, saying that made it impossible to properly assess witness credibility.

Earlier this month, the San Mateo County Board of Supervisors approved procedures that would allow them to remove a sheriff with a four-fifths vote.

It remains unclear when the removal hearings will begin, but county officials have said the process, once it is started, could take up to four months.