THE INCENTIVES THAT PROMOTE THE SYSTEM'S RELIANCE ON NEGOTIATED PLEAS OF GUILTY ARE EXPLAINED POINTING OUT THAT BECAUSE OF THE ABSENCE OF SIGNIFICANT PRETRIAL DISCOVERY, THE SYSTEM EXTRACTS UNKNOWING WAIVERS OF CONSTITUTIONAL RIGHTS. AN OVERVIEW OF THE CALIFORNIA PRETRIAL PROCESS AND THE FORMAL AND INFORMAL MECHANISMS THROUGH WHICH PRETRIAL CRIMINAL DISCOVERY OCCURS IS PRESENTED. THE INCREASED IMPORTANCE OF THE PRELIMINARY HEARING IN THE PLEA BARGAIN SYSTEM OF JUSTICE AND THE REASONS WHY IT HAS NOT FUNCTIONED ADEQUATELY AS A DISCOVERY PROCEEDING ARE DISCUSSED. SUGGESTIONS ARE MADE FOR SPECIFIC REFORMS IN THE OPERATION OF THE PRELIMINARY HEARING IN CALIFORNIA DESIGNED TO INCREASE THE AMOUNT OF BARGAINING INFORMATION AVAILABLE TO DEFENDANTS AND TO ENSURE ADEQUATE PROTECTION OF CONSTITUTIONAL RIGHTS. (AUTHOR ABSTRACT MODIFIED)