Gov. Code, § 54957

(a) (1) This chapter does not prevent the legislative body of a local agency from holding closed sessions with the Governor, Attorney General, district attorney, agency counsel, sheriff, or chief of police, or other law enforcement or security personnel, or a security consultant or a security operations manager, on matters posing a threat to the security of public buildings, a threat to the security of essential public services, including water, drinking water, wastewater treatment, natural gas service, and electric service, a threat to the public’s right of access to public services or public facilities, or a threat to critical infrastructure controls or critical infrastructure information relating to cybersecurity.

(2) For purposes of this subdivision, the following definitions apply:

(A) “Critical infrastructure controls” means networks and systems controlling assets so vital to the local agency that the incapacity or destruction of those networks, systems, or assets would have a debilitating impact on public health, safety, economic security, or any combination thereof.

(B) “Critical infrastructure information” means information not customarily in the public domain pertaining to any of the following:

(i) Actual, potential, or threatened interference with, or an attack on, compromise of, or incapacitation of critical infrastructure controls by either physical or computer-based attack or other similar conduct, including, but not limited to, the misuse of, or unauthorized access to, all types of communications and data transmission systems, that violates federal, state, or local law or harms public health, safety, or economic security, or any combination thereof.

(ii) The ability of critical infrastructure controls to resist any interference, compromise, or incapacitation, including, but not limited to, any planned or past assessment or estimate of the vulnerability of critical infrastructure.

(iii) Any planned or past operational problem or solution regarding critical infrastructure controls, including, but not limited to, repair, recovery, reconstruction, insurance, or continuity, to the extent it is related to interference, compromise, or incapacitation of critical infrastructure controls.

(b) (1) Subject to paragraph (2), this chapter does not prevent the legislative body of a local agency from holding closed sessions during a regular or special meeting to consider the appointment, employment, evaluation of performance, discipline, or dismissal of a public employee or to hear complaints or charges brought against the employee by another person or employee unless the employee requests a public session.

(2) As a condition to holding a closed session on specific complaints or charges brought against an employee by another person or employee, the employee shall be given written notice of their right to have the complaints or charges heard in an open session rather than a closed session, which notice shall be delivered to the employee personally or by mail at least 24 hours before the time for holding the session. If notice is not given, any disciplinary or other action taken by the legislative body against the employee based on the specific complaints or charges in the closed session shall be null and void.

(3) The legislative body also may exclude from the public or closed meeting, during the examination of a witness, any or all other witnesses in the matter being investigated by the legislative body.

(4) For the purposes of this subdivision, the term “employee” shall include an officer or an independent contractor who functions as an officer or an employee but shall not include any elected official, member of a legislative body or other independent contractors. This subdivision shall not limit local officials’ ability to hold closed session meetings pursuant to Sections 1461, 32106, and 32155 of the Health and Safety Code or Sections 37606 and 37624.3 of the Government Code. Closed sessions held pursuant to this subdivision shall not include discussion or action on proposed compensation except for a reduction of compensation that results from the imposition of discipline.