The Grand Jury is responsible for, but not limited to, watching over other departments of County government. This includes the District Attorney's Office and the Sheriff. They also periodically file public reports with the court describing the results of their various investigations.
Any kind of felony case can be brought before the Criminal Grand Jury, but only the more serious cases are typically reviewed by them. Since its inception, the Criminal Grand Jury has investigated hundreds of felony cases in Contra Costa County.
The Grand Jury has the lawful authority to investigate misfeasance (negligent conduct) and malfeasance (criminal conduct) committed by individuals.
If that individual is a public official, the Grand Jury could return an "Accusation" with the court, accusing that official of misfeasance.
If a trial jury should ultimately find the allegations in the Accusation true, the public official is removed from office.
If the Grand Jury should find an individual (whether he or she is a public official or not) committed criminal acts, the Grand Jury could return an "Indictment" to the court charging that individual with a crime.
If a trial jury should ultimately find the allegations in the Indictment true, the person charged would be sentenced by the court according to the penalties prescribed for the crime committed.