The Chicago Police Department partly blames the breakdown of well-organized gangs for the increase in violence this calendar year. Gang leaders were sent to prison, and Police Superintendent Garry McCarthy says a "fracturing" of gangs has lead to conflicts over issues such as territorial disputes.

CPD reports that through late May there have been 203 homicides in 2012, compared with 134 over the same period in 2011. This 50 percent increase reverses a long-term decline in reported Chicago murders since the early 1990's, when the city's homicide rate peaked.