INITIAL ANALYSIS OF THE IMPACT OF THE 1975 MASSACHUSETTS GUN CONTROL LAW EXAMINED MONTHLY DATA ON THE NUMBER OF GUN OFFENSES COMMITTED IN BOSTON. USING THE DELTA SHIFT DETECTION APPROACH, THIS ANALYSIS DETERMINED THE MAGNITUDE OF THE STATUTE'S EFFECT. HOWEVER, IT DID NOT ASCERTAIN WHETHER THE LAW HAD A LASTING INFLUENCE ON GUN OFFENSES. THEREFORE, A SUBSEQUENT RE-ANALYSIS OF DATA UP TO 1977 USED DYNAMIC INTERVENTION MODELING TO ADDRESS THE NATURE OF CHANGES IN THE CRIME RATES AND FOCUSED ON WHETHER THE CHANGES WERE PERMANENT OR TRANSIENT. MODELS FOR THE TIME SERIES DATA OF GUN-RELATED CRIME COMMITTED IN BOSTON USED AN IDENTIFICATION ALGORITHM WHICH DID NOT REQUIRE RESEARCHERS TO ARBITRARILY POSTULATE THE DYNAMIC COMPONENT FORM. WITH THE AID OF THE IDENTIFICATION PROCEDURE THE DYNAMIC INTERVENTION COMPONENT FOR EACH OF THREE OFFENSES EXHIBITED A CONSTANT REDUCTION IN THE CRIME ACTIVITY RATE. THIS REDUCTION WAS SEEN TO BE A PERMANENT CHANGE IN LEVEL THAT CONTINUED FOR 2.5 YEARS AFTER THE ENACTMENT OF THE GUN CONTROL LAW. FOR THE ANALYZED OFFENSES, THE RESEARCH NOTED REDUCTIONS OF 18 TO 29 PERCENT. DETAILED DESCRIPTIONS ARE PROVIDED OF THE STATISTICAL METHODOLOGIES USED IN THE RESEARCH. TABULAR DATA AND FIGURES DESCRIBE THE ALGORITHM AND THE CRIME RATES. REFERENCES ARE PROVIDED. (TWK)