San Mateo County jurors are sworn in and begin their one-year term commencing the first day of July. The Grand Jury Judge appoints a foreperson to preside at meetings. The jury then chooses the remaining officers and organizes itself into committees. Each committee sets its own program of committees, investigations and interviews. The committee then investigates various departments and functions of local government as it chooses and reviews compliance with previous Civil Grand Jury recommendations. Department heads are interviewed, on-site visits are made and departments' strengths and weaknesses are investigated.

Some subjects to be investigated are brought about by letters from citizens regarding complaints of alleged mistreatment by officials, suspicion of misconduct or governmental inefficiencies. Such complaints are kept confidential. If the situation warrants, and after investigation, the Grand Jury may make appropriate recommendations for action.

A large portion of the public mistakenly believes that an individual appearing before the Civil Grand Jury, particularly a public official, suggests malfeasance or misfeasance. It should be clearly understood that it is the constitutional responsibility of the Grand Jury to review the conduct of county government each year. This entails having public officials appear before the jury to provide information to the jury relative to their departments or offices.

While Grand Jurors are a part of the Judicial System and are considered as officers of the court, the Grand Jury is an entirely independent body. The Grand Jury Judge, the District Attorney, the County Counsel, and the State Attorney General act as advisors, but cannot limit actions of the jury except for illegality.

Because of the confidential nature of a Grand Jury's work, much of it must be done in closed session. Members of a Grand Jury are sworn to secrecy, thus assuring all who appear that their complaints will be handled in an entirely confidential manner. No one may be present during sessions of the Grand Jury except those specified by law (Penal Code 939), and the minutes of its meetings may not be inspected by anyone, nor can its records be subpoenaed.

The law provides that every Grand Juror must keep secret all evidence adduced before the Grand Jury, anything said by a Grand Juror or the manner in which a grand juror may have voted on a matter. By law it is a misdemeanor to violate the secrecy of the Grand Jury room. A Grand Juror must not confide any information concerning testimony of witnesses or action of the jury even to a spouse or close friend. "Leaks" concerning Grand Jury proceedings inevitably will impair or even destroy the effectiveness of Grand Jury efforts.

Mid-year and final reports are prepared that describe problems and contain findings and recommendations. Responses are required within 90 days from any public agency, and 60 days from any elective county officer or agency head.