In a letter sent to all five supervisors on Thursday, Rosen said the board twice violated the Brown Act, which requires public access to government meetings.
The board failed to disclose to the public ahead of a closed session on Oct. 17 that it was considering appointing a new executive to replace CEO Jeff Smith, who's retiring on July 1, 2023.
The board broke the rules a second time, argued Rosen, when it failed to immediately report its vote to appoint County Counsel James Williams to the position at a public meeting on Oct. 18.
The DA's letter came days after San Jose Spotlight's exclusive reporting on one of the Brown Act violations, informing the board it has 30 days to remedy the violations, or the DA would sue the board for breaking the law.
At the Nov. 1 meeting, when the public first heard about Williams' appointment, supervisors repeatedly said they unanimously voted to pick the new county CEO on Oct. 17, which was validated in a county document.
Supervisor Susan Ellenberg previously told San Jose Spotlight the board misspoke, adding the action taken in closed session on Oct. 17 was only an authorization for some supervisors to meet with Williams and negotiate his employment agreement.
On Friday, Ellenberg acknowledged the DA's letter and vowed to remedy the violations. The board is scheduled to meet in closed session later today to discuss the letter.
