Overall, though, things haven't changed much from the past several years, at least judging by the number of homicides committed in major cities. While the number of homicides has increased in many big cities, the increases are moderate, not more than they were a few years ago. Meanwhile, crime has declined in other cities.
Overall, most cities are still far safer than they were two decades ago, and virtually all of that improvement has remained. That's when the rate of violent crime began a long, steep decline nationally. Although violent crime has been decreasing overall, the general trend hasn't been uniform. The data on crime so far this year does not show clearly that the trend toward safer streets is ending or reversing.
The total number of homicides in 2013 and 2014 in the 10 largest cities was 1,871 and 1,889 respectively. If current trends continue, there will be 2,178 homicides in those cities this year. That number would be less than the total for 2012 (2,224) and for any previous year since at least 1985 in those 10 cities.
"Crime and violence in most big cities in the United States are pretty much as they've been lately," said Franklin Zimring, a criminologist at the University of California, Berkeley. "Boy, is that good news."
That said, there are at least three cities where the statistics so far this year are indeed deeply worrisome. If current trends continue, Baltimore, Milwaukee and St. Louis this year stand to lose more than 20 years of progress in preventing homicide. The dotted lines in these charts represent projections of murder trends based on the percentage change between the number homicides since January and the number during the same period last year.
All three cities have been the site of protests over the deaths of black residents at the hands of police, which has led some law enforcement officers and commentators to suggest that police are now too cautious to do their jobs properly. Indeed, in Baltimore, police have been making far fewer arrests since several officers were charged in connection with the death of Freddie Gray in police custody.
"There's a real public pressure to start to hold them accountable, and that's a good thing," he added. "What we’ve seen is, because police are being held accountable, a tendency or possibility that the police are backing off."
This explanation can't entirely account for the data in Milwaukee and St. Louis, where violent crime rates were already elevated before the shooting deaths of Dontre Hamilton and Michael Brown Jr. last year in altercations with police.
"Homicides were going up before Michael Brown was killed, and the same is largely true for other violent crimes," said Richard Rosenfeld, a criminologist at the University of Missouri, St. Louis.
It also isn't clear if the trend in these three cities is national in scope. While there have certainly been more homicides this year than last in most of the country's largest cities, the number of homicides always changes from year to year.
The largest cities, at least, are still very safe. Increases this year follow two years in which police in major cities — especially New York, Los Angeles, and Chicago — recorded fewer homicides than they had in decades.
This chart shows a few of the cities with the most homicides. Other large cities with moderate increases include Dallas, Houston, Phoenix, San Francisco, and San Antonio.
In several other large cities, meanwhile, detectives are investigating fewer deaths this year than last year. The number of homicides in Indianapolis has declined sharply, which is welcome relief for residents of a city in which violent crime has been steadily increasing for several years.
An important caveat is that data on reliable crime in the United States is hard to come by.
The charts in this post rely on the Uniform Crime Report, published annually by the Federal Bureau of Investigation. Critics say the report is incomplete and inconsistent from jurisdiction to jurisdiction. The most recent data from the bureau is for 2013, and the figures for 2014 in the charts are based on various news reports and preliminary data from police departments, which could be inaccurate.
Finally, as noted, data for this year has been projected based on the percentage change between the number homicides since January and the number during the same period last year. The remainder of the year could bring new developments in the rate of homicides.
In general, though, the trend is clear. The number of homicides in major U.S. cities has declined spectacularly, and the streets appear much safer than they were just a few years ago. As for the recent increase in crime, it isn't yet clear whether the number of homicides in Baltimore is just an outlier, a result of tense relations between police and civilians, or a harbinger of a reversal in the national trend.
Just a few years ago, these homicide figures would have been unremarkable — particularly as those killed are disproportionately black, a group of victims who are often invisible to the press.
"Those black lives matter also," said Blumstein of Carnegie Mellon.
This year, though, a number of news organizations have covered the data in detail, including USA Today, Reuters, CNN, and National Review as well as The Times. The fact that homicides are becoming a major national news story itself is an indication of how much progress the country has made in thinking about and preventing violence in the inner city.