Information is presented on a county grand jury in California where its mandated responsibilities are to act as a watchdog agency and to investigate county executive departments for purported inefficiency, wrongdoing and corruption. Until 1977, grand jury members in Santa Barbara County were nominated by Superior Court judges. Then the volunteer system, whereby any citizen could volunteer to become a grand juror, was instituted. It is hypothesized that the volunteer grand juries are more effective (i.e., have a higher compliance rates to its recommendations to county departments) than nonvolunteer grand juries. Evidence indicates that the volunteer grand jury has a statistically higher rate of compliance to its recommendations than do the nonvolunteer grand juries. These findings lend tentative support for the continued usage of volunteers rather than nonvolunteers as grand jurors as a means of promoting representativeness and efficiency in carrying out the grand jury's tasks. (Publisher abstract)