Here’s a PolitiFact headline that was published on June 9th: “Donald Trump said, ‘Crime is rising.’ It’s not (and hasn’t been for decades).”

The fact-checking site gave Trump a “Pants on Fire” rating for his statement. When critics responded that there was evidence of a recent spike in violent crime generally and homicides in particular, PolitiFact stood by its rating, noting that the evidence cited was “preliminary and subject to revision. Two criminologists we checked with before publication warned us that such data may not be indicative of a real trend.”

Well, we now have full-year data for 2015and it turns out that PolitiFact’s initial declaration was embarrassingly wrong.

Yesterday the FBI reported that the total number of murders nationwide increased by 10.8 percent last year, which — as the Guardian observed — is the largest annual increase since 1971. The murder rate, meanwhile, jumped to 4.9 per 100,000 people from 4.4 per 100,000 in 2014.

As crime analyst Jeff Asher points out at FiveThirtyEight:

The increase in murder was remarkably widespread. Of the 82 cities with populations over 250,000 in 2014 or 2015, 52 experienced a rise in murder last year; murder fell in only 26. (Four cities stayed the same.) Murder rose by double digits in 29 big cities last year while dropping by double digits in just four of them. Three cities (Indianapolis; Louisville, Kentucky, and Omaha, Nebraska) had more murders in 2015 than in any of the last 40 years. Preliminary evidence suggests the murder rate is continuing to rise in 2016, at least in the largest cities.

To be sure, the U.S. murder rate in 2015 was still lower than at any point between 1965 and 2009, and it was only half the rate in 1991. Similarly, while the overall violent-crime rate was higher in 2015 than in 2014 or 2013, it was lower than at any point between 1971 and 2012.

So the long-term trends remain encouraging. But the trends since 2014 are deeply concerning.

“People say to me, ‘Well, the increases are off of historic lows,’” FBI director James Comey told reporters in May. “How does that make any of us feel any better? I mean, a whole lot more people are dying this year than last year, and last year than the year before, and I don’t know why for sure.”

In an October 2015 speech at the University of Chicago Law School, Comey said he had “a strong sense that some part of the explanation is a chill wind blowing through American law enforcement over the last year. And that wind is surely changing behavior.”

This “chill wind” has become known as “the Ferguson effect.” First popularized by Manhattan Institute scholar Heather Mac Donald, the theory is that the backlash following the August 2014 death of Michael Brown in Ferguson, Missouri, led to a reduction in proactive policing and served to embolden violent criminals. In a June 2016 study published by the Justice Department, criminologist Richard Rosenfeld of the University of Missouri–St. Louis concluded that, given the timing of the homicide surge, some version of the Ferguson effect seemed a more likely explanation than either “expanding urban drug markets” or “declining imprisonment rates.”

Whatever the explanation, rising crime is a very real problem in many U.S. cities. After Monday’s FBI report, it’s no longer possible to deny that.