The sheriff of San Mateo County has asked the president of the county’s Board of Supervisors for an independent investigation of County Executive Mike Callagy for alleged interference in her office that she said is undermining her authority.

Sheriff Christina Corpus is herself under investigation by someone appointed by the Board of Supervisors over discord with the San Mateo County Deputy Sheriff’s Association representing rank-and-file deputies.

The board commissioned a retired judge to lead an independent investigation “into the numerous complaints brought forward by both sworn and professional staff members of the San Mateo County Sheriff’s Office,” the board said.

The sheriff responded Sunday.

“I was elected by the people of San Mateo County to enact necessary reforms in the Sheriff’s Office,” Corpus said in a letter to Supervisor Warren Slocum, president of the board. “Culture change is never easy, and resistance from certain individuals — rooted in outdated practices from previous administrations — is expected.

“But what is unacceptable is Mr. Callagy’s support of this resistance, his interference with personnel decisions, and his continuous efforts to undermine my leadership,” the sheriff said. 

The county executive’s office was not immediately available to comment on the sheriff’s allegations Sunday.

The latest dispute centers on Corpus’s firing of her third-in-command, Assistant Sheriff Ryan Monaghan, who is not part of the union. Supervisor Ray Mueller on Friday alleged that the firing appeared to be retaliation against Monaghan for speaking to LaDoris Cordell, the retired judge investigating the Sheriff’s Office.

Earlier this month, the board hired Cordell to investigate complaints against the sheriff’s department just three days after holding a no-confidence vote in the department’s chief of staff. She recently interviewed Monaghan.  

The Board believes the Sheriff Christina Corpus became aware of the interview shortly before firing Monaghan. 

“The timing of the Sheriff’s action and information provided by Assistant Sheriff Monaghan suggest possible retaliation against Assistant Sheriff Monaghan for participating in Judge Cordell’s independent investigation,” Mueller said.

‘Completely out of line’

Corpus called the allegation “pure speculation” that was “completely out of line.”

In her letter, Corpus said Callagy issued a directive to block Monaghan’s termination, “a decision squarely within my authority and purview as the elected sheriff and involving an at-will and unclassified employee.”

She complained that Callagy, who is not elected, “has continued to overstep his authority, routinely inserting himself into the operations of the Sheriff’s Office. He has supported the group of employees referred to as the good ol’ boy system from the previous administration and has empowered them.”

The union has complained that the Sheriff’s Office changed its minimum staffing level policy without union input and refused to meet about an expiring overtime policy.

President of the San Mateo County Deputy Sheriffs Association, Carlos Tapia, speaking about what has caused the union’s fractured relationship with the San Mateo County Sheriff’s Office administration at the County Center in Redwood City, Calif. on Tuesday, Sept. 17, 2024. (Alise Maripuu/Bay City News)

The sheriff said Callagy “treated me not as an elected official but as if I were one of his subordinates” and allegedly made an offensive request.

“Mr. Callagy told me that I had to inform him of when and who I dated within the county — a request I found not only offensive but demeaning and discriminatory,” Corpus said. 

“As a woman of color who has endured sexual harassment in this very county, I was shocked and appalled by his inappropriate conduct. I cannot imagine he would have made such a request of my predecessors, all of whom were men.”

Bay City News staff reporter Grace Marion contributed to this report.