A growing body of literature suggests that crime is both concentrated in a small number of geographic units, and committed by a small number of people, within American cities. A related body of empirical evidence, dating back almost three decades, suggests that police can effectively combat violent crime in hot spots by focusing resources within them. The current study evaluates the impact of a hot spots policing strategy in Dallas, Texas as part of a comprehensive, city-wide strategic plan to reduce violent crime. Using difference-in-differences techniques, we find consistent evidence that violent crime fell, on average, by 11% in targeted hot spots during the first year of the Dallas Crime Plan with no evidence of spatial crime displacement to adjacent areas. Effects varied somewhat by treatment type. The offender-focused treatment was somewhat more effective than the high visibility treatment alone, but both reduced crime by statistically significant amounts. Arrest analyses likewise revealed differential impacts by treatment type, with significant arrest reductions seen in high visibility treatment areas consistent with deterrence and arrest increases in offender-focused areas consistent with the strategy's focus on violent offenders. The contribution of the targeted hot spots to city-wide violent crime decreased significantly over the course of the year, which provides inferential evidence of the strategy's possible city-wide impact on violent crime. Implications of the study for policy, practice, and future research are discussed.

越来越多的文献表明，犯罪既集中在美国城市内的少数地理单位，也由少数人实施。近三十年前的相关经验证据表明，警方可以通过在热点地区集中资源来有效打击热点地区的暴力犯罪。目前的研究评估了德克萨斯州达拉斯市热点警务策略的影响，作为减少暴力犯罪的全面全市战略计划的一部分。使用双重差分技术，我们发现一致的证据表明，在《达拉斯犯罪计划》实施的第一年，目标热点地区的暴力犯罪平均下降了 11%，但没有证据表明犯罪空间转移到邻近地区。效果因治疗类型的不同而有所不同。以犯罪者为中心的治疗比单独的高可见度治疗更有效，但两者都显着减少了犯罪数量。逮捕分析同样揭示了不同处理类型的不同影响，在高能见度的处理区域中逮捕人数显着减少，与威慑一致，而在以犯罪者为中心的地区逮捕人数增加，这与该战略对暴力犯罪者的关注一致。年内，定向热点地区对全市暴力犯罪的贡献明显下降，这为该策略可能对全市暴力犯罪产生影响提供了推论。讨论了该研究对政策、实践和未来研究的影响。