THIS STUDY IS BASED ON 15 MONTHS OF FIELD WORK, FROM MARCH 1974 TO JUNE 1975, IN THE COUNTIES OF ALAMEDA AND SAN DIEGO. THESE TWO COUNTIES ARE QUITE SIMILAR, WITH REGARD TO POPULATION AND SIZE, BUT THE TYPES OF CRIME ARE DIFFERENT. ALAMEDA COUNTY, WHICH INCLUDES THE CITY OF OAKLAND, HAS A MORE SERIOUS AND VIOLENT TYPE OF CRIME, WHILE SAN DIEGO COUNTY IS JUST BEGINNING TO EXPERIENCE THESE CRIMES. THE MAIN FOCUS IS ON PLEA NEGOTIATIONS IN THE TWO AREAS. THE 'ADMINISTRATIVE MODEL' DESCRIBES STRAINING FOR COOPERATION BETWEEN THE PROSECUTION AND DEFENSE, BUT THE ACTUAL PATTERNS OF BARGAINING DO NOT REFLECT THIS COOPERATION: THEY ARE MORE INDICATIVE OF THE OLD ADVERSARY SYSTEM. PLEA BARGAINING IS FLAWED WITH ABUSES, SO AN ALTERNATIVE DIAGNOSIS IS SUGGESTED. IN SAN DIEGO COUNTY, ADVERSARY BARGAINING IS THE NORM. IT DOES NOT REFLECT THE INNER DYNAMICS OF PLEA BARGAINING, BUT ACTUALLY REFLECTS THE INHIBITING CONDITIONS THAT CONSTRAIN THE PRACTICE. ON THE OTHER HAND, ALAMEDA COUNTY HAS A FULL-FLEDGED BARGAINING SYSTEM. IT IS A FORM OF EVOLVED PROFESSIONALISM, BASED ON RATIONAL AND GENUINE COOPERATION BETWEEN ATTORNEYS. NEGOTIATION HAS BROUGHT A DEFINITE CONTRIBUTION TO SUBSTANTIVE JUSTICE, THAT OF MORE PRINCIPLED NEGOTIATION. NOTES ARE PROVIDED. (BAC)