Violent crime increased in the United States for a second consecutive year in 2016, remaining near historically low levels but pushed upward in part by an uptick in killings in some major cities, according to FBI statistics made public Monday.

The FBI’s release of the figures comes as the Trump administration has warned ominously of a dangerous crime wave. In his inaugural address, President Trump described “American carnage” in U.S. cities, while Attorney General Jeff Sessions said earlier this year he worried the increase in crime was “the beginning of a trend.”

Some experts and analysts have disputed that suggestion, noting that crime levels were much higher a quarter-century ago and pointing out that the recent increases are not universal. In some major cities, violence has surged, while in others it has declined. Chicago, a much-cited example, saw a spike in murders last year, as did Las Vegas and Louisville; killings dropped, meanwhile, in places including New York, Cincinnati and Newark.

The FBI statistics for 2016 show that the estimated number of violent crimes nationwide increased 4.1 percent over the previous year. The violent crime rate was 386.3 offenses per 100,000 inhabitants, up from 373.7 a year earlier, and the highest figure since 2012. Murder and non-negligent manslaughter was up 8.6 percent over 2015, the FBI data show, and the murder rate increased to 5.3 per 100,000 people, the highest that figure has been since 2008. Firearms were once again used in most killings.

In the violent crime and murder rates alike, the numbers reported last year were well below figures seen during previous decades. Going back to the mid-1980s, the violent crime and murder rates were both consistently higher, particularly in the early 1990s. In 1991, for instance, the violent crime rate was 758.2 per 100,000 people, and the murder rate was 9.8 per 100,000 people, after which both numbers began to fall, albeit with some year-over-year increases.

The FBI considers four crimes — murder and non-negligent manslaughter, rape, robbery and aggravated assault — to be violent crimes involving force or the threat of force.

Looking more recently, the statistics released Monday show that the violent crime rate in 2016 was down 18 percent from 2007, while the murder rate was down 6 percent over the same period.

Sessions, who has tied some of his policy pushes to the increase in crime, said Monday that the Justice Department would fight what he described as a “rising tide of violent crime” nationwide.

“For the sake of all Americans, we must confront and turn back the rising tide of violent crime. And we must do it together,” Sessions said in a statement. “The Department of Justice is committed to working with our state, local, and tribal partners across the country to deter violent crime, dismantle criminal organizations and gangs, stop the scourge of drug trafficking, and send a strong message to criminals that we will not surrender our communities to lawlessness and violence.”

In a news release containing Sessions’s statement, the Justice Department said that the data released Monday “reaffirms that the worrying violent crime increase that began in 2015 after many years of decline was not an isolated incident.”

Richard Berk, a professor of statistics and criminology at the University of Pennsylvania, disputed the suggestion that the national numbers suggested any sort of trend, pointing out that crime occurs on a local level.

“The fundamental thing is, national summaries are really sort of empty calories,” Berk said Monday. “There’s no real information in there to guide policy, or citizen concerns, because the action is all very local.”

Berk added: “Some cities that have more problems than others, and in those cities some neighborhoods have more problems than others, and to talk about national anything is just politics.”

The Brennan Center for Justice, a New York-based law and policy institute, said Monday that the murder rate increase was fueled by an increase in killings in some of the country’s largest cities — with Chicago accounting for more than a fifth of the nationwide murder increase last year.

“The FBI’s data show trends similar to what we’ve found for crime, murder, and violence in 2016,” Ames Grawert, a counsel in the Brennan Center’s Justice Program, said in a statement Monday. “Crime remains near historic lows, with an uptick in murder and violence driven in part by problems in some of our nation’s largest cities. At the same time, other cities like New York are keeping crime down.”

The Brennan Center released an analysis earlier this month saying that the violent crime rate and murder rate are both expected to decline in 2017. The center had said that individual cities could play an outsize role in impacting the overall crime rates, saying the 2015 surge in killings was fueled by just three cities — Chicago, Baltimore and Washington. Last year, the center reported that the increased homicide rate for the country’s 30 biggest cities was in large part due to Chicago, finding that it was responsible for nearly half of this increase.

Homicides went up in last year more than three dozen of the country’s biggest cities or counties, according to data collected by the Major Cities Chiefs Association, the group of law enforcement leaders. That included Chicago, which had 762 homicides in 2016, up from 482 homicides a year earlier, along with cities such as Phoenix and Louisville.

Other cities reported declines, including New York, the country’s largest city, which reported 335 murders last year, down from 352 a year earlier and less than half the 673 murders reported in 2000. The city is continuing that this year, with 192 murders reported through Sept. 17, down from 250 at the same point a year earlier. Cities including Portland and Minneapolis were also among those reporting fewer homicides last year as well.

Across the country, leaders of law enforcement agencies have attributed the increase in violence to gang activity, opioids and heroin and “the overwhelming presence of guns,” said Darrel Stephens, executive director of the Major Cities Chiefs Association and a former Charlotte police chief.

Stephens said that Sessions’s concerns about violent crime are understandable, noting that the attorney general has met with police chiefs who have concerns about violence, including those from cities where the homicide counts have not been increasing.

“He’s heard those concerns from big city police chiefs, he’s met with them,” Stephens said Monday. “I’ve been in some of those meetings, and they do talk about that. But even in cities that aren’t having increases in violent crime, they still have a level of violent crime that they find, and most of the communities find, is not acceptable. Those violent crimes still take place in high poverty neighborhoods. It is a continued source of concern even if they’re not experiencing the big increases.”

Still, Stephens offered a note of cautious optimism for 2017, noting that data collected by the Major Cities Chiefs Association showed fewer cities were reporting homicide increases at the halfway point of the year, and some of those that were have seen smaller jumps.

“This year’s a little better so far,” Stephens said. “The increases don’t seem quite as bad as they were in the past. It’s hard to say for sure but I’m thinking that by the time we get ourselves to the end of this year, it’s not going to look like 2016, it’s going to look a little bit better.”

In a message accompanying the statistics Monday, FBI Director Christopher A. Wray focused largely on increasing transparency, particularly when it comes to how police use force, an issue that has roiled the country in recent years. He noted that the FBI had created a database to collect use-of-force statistics for law enforcement, which will include any encounter that ends with a person killed, seriously injured or when a gun is fired at them.

“Our goal is that this data will lead to more informed and accurate discussions within our communities and the media and that these discussions will foster more transparency and improve communications between law enforcement and the communities they serve,” Wray wrote.

The FBI’s statistics on deadly uses of force by police have long been known to be incomplete. The FBI reported that last year, 435 people were killed in justifiable homicides by law enforcement officers. The Washington Post’s database tracks all deadly police shootings and was launched in part due to the lack of any federal system logging such killings, found at least 963 fatal shootings carried out by police officers last year.

Sessions has tied the recent increase in violent crime to “undermined” respect for police officers and, in a recent speech, connected Chicago’s crime rates to the city’s policies on undocumented immigrants, a contention disputed by the police there.

In other categories, the FBI statistics released Monday showed positive signs. Property crimes dropped by 1.3 percent, the data show, the 14th consecutive year that figure fell. Burglary and larcenies fell, the FBI reported. But along with murder and non-negligent manslaughter, the FBI reported that rape and aggravated assault both increased in 2016.

The FBI’s data was compiled in an annual report called “Crime in the United States,” which collects information reported voluntarily by law enforcement agencies to the bureau’s Uniform Crime Reporting Program.

This story, first published at 9:16 a.m., has been updated with additional information.

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