President Trump speaks during a news conference last week at the White House in Washington. (Nicholas Kamm/Agence France-Presse via Getty Images)

President Trump would have us believe that crime has reached epidemic proportions and is related to so-called sanctuary cities (a term that has no definition and is therefore of limited value anyway). Neither view is right. Now, a substantial study on crime in the 30 biggest U.S. cities shows how wrong he is.

The Brennan Center for Justice at New York University School of Law, utilizing FBI crime statistics and city police records, found:

Crime has dropped precipitously in the last quarter-century. While crime may fall in some years and rise in others, annual variations are not indicative of long-term trends. While murder rates have increased in some cities, this report finds no evidence that the hard-won public safety gains of the last two and a half decades are being reversed.

The national crime rate peaked in 1991 at 5,856 crimes per 100,000 people, and has generally been declining ever since. In 2015, crime fell for the 14th year in a row. Estimates based on preliminary data for 2016 indicate that the overall crime rate will remain stable at 2,857 offenses per 100,000, rising less than 1 percent from 2015. Today’s crime rate is less than half of what it was in 1991.

The general trend for violent crime and for murder is similar. With regard to murder, however, here is the wrinkle:

From 1991 to 2016, the murder rate fell by roughly half, from 9.8 killings per 100,000 to 5.3. The murder rate rose last year by an estimated 7.8 percent. With violence at historic lows, modest increases in the murder rate may appear large in percentage terms. Similarly, murder rates in the 30 largest cities increased by 13.2 percent in 2015 and an estimated 14 percent in 2016. These increases were highly concentrated. More than half of the 2015 urban increase (51.8 percent) was caused by just three cities, Baltimore, Chicago, and Washington, D.C. And Chicago alone was responsible for 43.7 percent of the rise in urban murders in 2016. It is important to remember the relatively small base from which the percentage increases are calculated.

We don’t know with certainty what has caused the 25-year drop in crime, although many researchers, including those at the Brennan Center, say it is related to better — and more — policing, an aging population and decreased alcohol consumption. But rather than paint the entire country and all cities as awash in murder and violence, policymakers and voters should look at several data points.

Attorney General Jeff Sessions told a group of law enforcement officers in St. Louis that he fears crime rates in the United States could rise significantly on March 31. (Reuters)

First, it is important to remember that crime rates can be volatile, bouncing up and down for reasons that are not readily discernible. The overall trend, however, remains the same. For example: “In Las Vegas, the violent crime rate has been especially volatile. The rate surged between 1990 and 1994, then steeply declined until 2000. Yet, from 2000 to 2007 crime followed a largely upward trajectory, reaching another peak in 2007. Then crime fell until 2011, and followed another largely upward trajectory until 2015. Yet, the estimated 2016 rate dropped nearly 13 percent from 2015, and now is roughly at the same rate as in 1998.”

Second, the national murder rate is down — by a lot. “After peaking in 1991 at 9.8 murders per 100,000, the national murder rate remains near the bottom of a 25-year trend. In 2016, the estimated murder rate was 5.3 per 100,000, a decline of 46 percent. The murder rate in the 30 largest cities has fallen faster than the national rate, declining by more than 60 percent since 1991, from 28.8 to 11.4 killings per 100,000 people.”

Now, the president always talks about cities as scary, dangerous places where you get killed walking down the street. This may resonate with members of Trump’s white, rural voting base, who view urban America with suspicion and resentment (and who may harbor more racist views than non-Trump voters), but actually, the recent trend in rural America is troubling. In fact, the Brennan study staff members tell me that in 2015, counties with populations of less than 10,000 people saw violent crime increase by 2 percent. Counties with 10,000 to 25,000 people saw increases of 3.4 percent, although both overall have seen a drop in violent crime in the past five years.

Third, several cities have a big crime problem and an even bigger murder problem. “In 2015 and 2016, several cities — especially Chicago — saw their murder rates increase significantly. … Baltimore, Chicago and Houston together account for around half of the increase in murder in major cities between 2014 and 2016.”

Why some cities have done much worse than others and continue to see rising crimes rates is a matter of debate. In a separate study for 2015, the Brennan Center finds: “Only in a few cities are crime and murder projected to increase significantly together: Chicago, Louisville, Oklahoma City, and San Antonio. Other cities are projected to see murder rise while overall crime falls (San Diego), and others will see higher crime without any increase in murders (Charlotte). This indicates there may be a problem with murder in these specific cities, not that there is a national trend of rising crime.”

When one looks at the five cities that had the highest murder rate increases in 2015 (Baltimore, Chicago, Charlotte, Houston and Washington), a few specific factors stand out. In Chicago, for example, a low rate of closing out murder cases raises the possibility of repeat offenders, and a dramatic decrease in the number of police officers may play a substantial role as well. In addition, “Chicago homicides are concentrated in the most segregated and poorest areas of the city, such as the South Side and the Austin vicinity. … The ‘national’ increase in murders identified by this report, in other words, may owe more to profound local problems in a few Chicago neighborhoods than national trends.”

We know, however, that one factor had nothing to do with murder and crime rates: “sanctuary city” status. Arguably the biggest success story in crime and murder reduction, New York, is exceptionally protective of its illegal-immigrant population. Los Angeles falls into the same pattern (big reduction in crime, high level of protection for illegal immigrants). Blaming the illegal-immigrant population for crime is factually wrong, misleading and frankly designed to spur anger toward this population, thereby serving Trump’s xenophobic views.

In sum, violent crime and murder rates have declined dramatically in 25 years. A few very problematic cities are responsible for a recent spike in murders, and it would seem logical to focus on the factors in those cities that may contribute to the problem. To portray all cities as crime-ridden hellholes and immigrants as responsible, in the face of overwhelming evidence to the contrary, can only be characterized as ignorant and prejudiced.