The findings indicate that 44 percent of all terrorists studied lived within 30 miles of their targets. International terrorists lived relatively near their targets; whereas, right-wing terrorists lived in rural areas but selected targets that reflected the "pollutants of urban life" in nearby cities. Terrorists most often prepared for their attacks through surveillance and intelligence collection, robberies and thefts to raise funds for group activities, weapons violations, and bomb manufacturing. Most of these preparatory activities occurred relatively near where the terrorists were living, which was close to the targets for approximately half of the cases studied. Among single-issue terrorists in particular, 71 percent of the preparatory activities occurred within 12 miles of their targets, and 92 percent of the preparatory activities occurred within 28 miles of the target. Robberies, burglaries, and thefts, however, were committed much farther from terrorists' residences than other preparatory activities, an average of 429 miles. Preparations generally began less than 6 months before the time of the attack and concluded with a flurry of preparatory activities a few days before the attack. International terrorists engaged in nearly three times as many preparatory activities per incident as environmental terrorists. The findings on these patterns are significant for law enforcement counterterrorism tactics. Knowing that most preparatory activities by terrorist groups occur near their residences and their targets suggests that police agencies should identify high-risk terrorist targets within their jurisdictions and be alert to suspicious activities that might be observed and/or reported by citizens living or working in the vicinity of those targets. 3 figures, 1 table, and 9 notes