Statement of purpose This analysis seeks to describe the temporal and demographic trends of homicides in the City of Chicago.

Methods/Approach Data from the Illinois Violent Death Reporting System (IVDRS) were used for this analysis. Cases included: homicide victims in which the fatal injury occurred in Chicago, and the date of death occurred 2008–2016. Linear regression, ANOVA and Pearson’s chi-square were used to determine trends over time for number of homicides, age of homicide victims, and sex and race/ethnicity of homicide victims, respectively.

Results From 2015 to 2016, there was a 59.6% increase in the number of homicides in Chicago (515 to 822); increases were seen in all twelve calendar months, ranging from 7.8% (August) to 144.1% (October). From 2008 to 2016, there was not a significant trend over time in the number of homicides, overall or for any single calendar month, or by age of homicide victims. There was a significant, positive trend over time in the proportion of black (p=0.002) and male (p=0.043) victims. There was a significant, negative trend over time in the proportion of Hispanic victims (p=0.039). The proportion of homicide victims who were black and male increased significantly over time (p<0.001), and ranged from 63.2% in 2008 to 72.8% in 2016.

Conclusions Overall, from 2008 to 2016 there was no significant trend in homicides. However, the number of homicides in Chicago increased dramatically from 2015 to 2016, and more than doubled in February, October and November. Black males were disproportionately affected, and the disparity has increased significantly over time from 2008 to 2016.

Significance and Contributions to Injury and Violence Prevention Science This is a classic descriptive analysis which looks at temporal and demographic trends among victims of homicide in Chicago over time which allows a more nuanced understanding of the homicide epidemic in Chicago.