DATA USED IN THE PAPER CONSIST OF 825 ROBBERY TRIPS REPRESENTING 642 CLEARED ROBBERIES WHICH OCCURRED IN METROPOLITAN MIAMI IN 1971. ROBBERY TRIP DISTANCES WERE CALCULATED FOR EACH OF THE 825 OFFENDERS BY PLOTTING THE ORIGIN AND DESTINATION ON A DETAILED STREET MAP, CONVERTING THESE TO COORDINATE LOCATIONS, AND COMPUTED ACCORDING TO THE DISTANCE FORMULA. THE RESULTS REVEAL THAT ROBBERY MOVEMENT BEHAVIOR VARIES IN TERMS OF DISTANCE DEPENDING ON WHETHER THE OCCURRENCE IS ARMED OR UNARMED OR WHETHER IT TAKES PLACE IN OPEN SPACE OR INVOLVES A FIXED PREMISE AS THE TARGET. IT WAS SUGGESTED THAT ROBBERY TRIP DISTANCE IS A FUNCTION OF THE DISTRIBUTION OF OPPORTUNITIES (A SUBSET OF THE TOTAL URBAN STRUCTURE) AND THEIR DIFFERENT LEVELS OF ATTRACTIVENESS TO OFFENDERS. THE RELATIONSHIP AMONG OPPORTUNITY STRUCTURE, ATTRACTIVENESS, AND DISTANCE WERE DEMONSTRATED FOR CONVENIENCE STORE ROBBERY TRIPS, WHICH SHOWED SHORT DISTANCE TRIPS TO PREDOMINATE WHEN ATTRACTIVENESS WAS EQUAL, BUT A HIGH FREQUENCY OF RELATIVELY LONG DISTANCE TRIPS WHEN ATTRACTIVENES WAS GREATER. THE AUTHOR CONCLUDES THAT URBAN STRUCTURE AND CRIMINAL MOBILITY ARE INEXTRICABLY LINKED, FOR CRIMINAL MOVEMENT BEHAVIOR IS THE PRODUCT OF AN ESSENTIALLY RATIONAL SPATIAL DECISION-MAKING PROCESS THAT INVOLVES EVALUATION OF AN OBJECTIVE URBAN OPPORTUNITY STRUCTURE, THE DIFFERENTIAL ATTRACTIVENESS OF PARTICULAR ELEMENTS OF THAT STRUCTURE, AND THE UNIVERSAL CONSTRAINT OF DISTANCE. DESCRIPTIONS OF FURTHER RESEARCH THAT IS ALREADY PLANNED AND MORE THAT IS NEEDED ARE INCLUDED. (AUTHOR ABSTRACT MODIFIED)...EB