A new report has found that the rate of violent crime has increased in major U.S. cities when compared to last year.
The study was conducted by the Major Cities Chiefs Association, an independent organization of police executives that provides a forum for analysis and discussion of crime in urban America.
The MCCA compiled data from law enforcement in the 50 largest cities in the U.S. -- and a handful of other urban areas -- on the number of reported shootings, homicides, rapes, robberies, and assaults, according to CNN.
According to the analysis, each category of violent crime, with the exception of rape, is significantly more prevalent so far in 2016 than it was this time in 2015. The study reports about 300 more homicides, 1,000 more robberies, 2,000 more aggravated assaults, and 600 non-fatal shootings.
Chicago saw the largest changes, with a 48 percent increase in homicides. The city’s 316 killings so far this year is the most of any city in the survey.
CNN notes that the study was missing an important data point: the rates for New York City were not included because they were not available in time for the report, says the MCCA.
According to The Washington Post, the New York Police Department reports a slight decline in homicides and shootings this year.
Preliminary crime data from the FBI shows a similar increase in violent crime overall, with significant variation depending on the city. The New York Times says that experts are divided on the causes of the recent uptick in violent crime in some cities. Law enforcement officials have pointed to a rise in gang tensions, drug addiction, and poverty as roots of the growing violence.
FBI director James Comey has suggested that recent controversy over viral video footage of police shootings has made officers more hesitant to confront possibly violent suspects and, in turn, has allowed more homicides. His description of this so-called “Ferguson effect” drew criticism from a number of experts and activists.
Overall, most crime remains at historic lows compared to past decades. James Alan Fox, a criminologist at Northeastern University, told The New York Times that small bumps in the crime rate are actually a result of cities’ success in keeping the crime rate low, saying that it “can’t go to zero, and when you hit really low numbers, it can only go up.”