Geographic information systems enable the study of the spatial distribution of gun violence in American cities. While sociodemographic characteristics and disinvestment patterns have been correlated to their presence, little work has examined spatio-temporal patterns among them. Understanding where shootings are more likely to be fatal may be of great value to criminologists, urban planners, and emergency department researchers. In this paper, we leveraged a crime database for Milwaukee spanning 2006 to 2015, geocoding every crime to its reported location. We ran kernel density analysis on each dataset to derive the relative density of gun homicides and non-fatal shootings. We then created space–time cubes for each crime type. These cubes were used with ESRI’s emerging hot spot analysis tool, highlighting different types of hot and cold spots. We appended these results to individual parcels to study the relationship between shooting hot or cold spots and sociodemographic characteristics. Lastly, we identified ‘islands’ with relatively fewer lethal shootings inside gun homicide hot spots, exploring reasons for their differentiation. While hot spots occurred primarily in African American neighborhoods, the worst areas were in more transitional neighborhoods, perhaps where disinvestment had not yet fully taken hold. Neighborhoods with the highest rate of homicides to total shootings included the most heavily Hispanic neighborhoods in Milwaukee, while lower rates were found in predominately African American neighborhoods. This work introduces a nuance into the discussion on policing gun violence, giving researchers and practitioners a finer lens in which to examine where and why gun violence occurs.

地理信息系统能够研究美国城市枪支暴力的空间分布。虽然社会人口特征和撤资模式与其存在相关，但很少有工作研究它们之间的时空模式。了解哪些地方的枪击事件更有可能致命，对于犯罪学家、城市规划者和急诊科研究人员来说可能具有重要价值。在本文中，我们利用了 2006 年至 2015 年密尔沃基的犯罪数据库，对每个犯罪进行了地理编码，以找到其报告的位置。我们对每个数据集进行核密度分析，以推导出枪支凶杀案和非致命枪击案的相对密度。然后，我们为每种犯罪类型创建了时空立方体。这些立方体与 ESRI 的新兴热点分析工具一起使用，突出显示不同类型的热点和冷点。我们将这些结果附加到个别地块上，以研究拍摄热点或冷点与社会人口特征之间的关系。最后，我们确定了枪支凶杀案热点内致命枪击事件相对较少的“岛屿”，探索了它们分化的原因。虽然热点主要出现在非裔美国人社区，但最糟糕的地区是在过渡性更强的社区，也许撤资还没有完全站稳脚跟。凶杀率最高的社区包括密尔沃基的西班牙裔人口最多的社区，而以非裔美国人为主的社区的比率较低。这项工作为有关枪支暴力治安的讨论引入了细微差别，