The study data came from criminal court records for 1965-1967 and for 1975. The analysis included only the cases for which the records specified that the crime location, the offender location, and, where applicable, the victim's location were all in the county. The court files included 100 business robbery cases and 28 personal robbery cases for 1965-1967 and 104 business robberies and 75 personal robberies for 1975. The data analysis used point pattern techniques. The locations of robberies spread into outlying suburban areas between the 1960's and 1970's. The robbers' residences dispersed outward, and robbers also became more spatially mobile during the same period. The changing mobility patterns suggest that outlying areas that have little control over socioeconomic criminogenesis factors in other areas should concentrate their crime prevention efforts on reducing crime opportunities in their own neighborhoods by focusing on potential targets for crime. Tables, figures, maps, and 12 references.