(Scott Olson/Getty Images)

Mark Holden is general counsel and senior vice president at Koch Industries. Ronal Serpas is a former superintendent of the New Orleans and Nashville police departments and the chairman of Law Enforcement Leaders to Reduce Crime and Incarceration.

There has been a surge of assertions about rising crime recently. At the Republican convention in July, GOP nominee Donald Trump said, “Decades of progress made in bringing down crime are now being reversed by this administration’s rollback of criminal enforcement.” The Manhattan Institute’s Heather Mac Donald echoed these concerns, noting that homicides increased by nearly 17 percent in the 56 largest U.S. cities last year and citing sharp rises in Baltimore, Chicago and the District. In an op-ed in last Sunday’s Post, Sean Kennedy and Parker Abt made the same case.

As two strong conservatives, let us set the record straight. These statements on rising murders are highly misleading. The truth is that Americans are still experiencing hard-won historic lows in crime.

When examining statistics on crime, researchers evaluate several factors: overall crime, violent crime, homicide and property crime.

By 2014, violent crime had fallen by half from its 1991 peak. Property crime was down 49 percent. Crime overall was 66 percent lower in major cities. No one disputes this decades-long trend.

Moving on to 2015, crime data collected directly from police departments in the 30 largest cities show that crime overall was the about same as in 2014 (in fact, it was down 0.1 percent). Violent crime was up by 3 percent, and murder by 13 percent. This is reasonably consistent with the FBI’s June 2015 midyear report, which showed violence up 1.7 percent and murder up 6 percent nationally, and the oft-cited Justice Department study by criminologist Richard Rosenfeld that found murder to be up 17 percent in major cities in 2015.

These numbers put the 2015 murder rate near 2012 levels — still very near to all-time lows.

This rise in homicide is alarming on its face. But half of 2015’s murder increase occurred in Baltimore, Chicago and the District — the very cities that those pushing the crime panic repeatedly use as examples. While we must work to address the issues driving this unacceptable localized violence, it is not the norm. These cities are outliers. As for violent crime overall, half of 2015’s increase came from a spike in aggravated assaults in Los Angeles.

Turning to 2016, data from the Major Cities Chiefs Association show homicides rising 15 percent at midyear. But, again, Chicago caused nearly one-third of that increase. Additionally, the MCCA study relies on self-reporting and therefore does not include cities such as New York, where homicide decreased. And its focus on cities, where murder rates are usually higher, likewise must be taken into account. The report shows a partial slice of the picture, making it difficult to draw conclusions about 2016.

Donald Trump addressed the GOP convention in Cleveland, Ohio, July 21. The Republican presidential candidate spoke for more than one hour, we broke it down to less than five minutes. (Deirdra O'Regan/The Washington Post)

Two more cautionary notes. First, some yearly variation is normal. For example, 2005, 2006 and 2012 all saw rises in violent crime. Each time, crime rates flattened or dropped soon thereafter, and the downward trend continued. The same may be happening now. In 2015, New York’s murder rate rose, but it decreased in 2016, reversing the 2015 increase. Even in Baltimore, where murders rose sharply last year, homicide has fallen by 9 percent this year.

Second, with the murder rate at such historic lows, increases measured in percentages may be misleading. Context is important. Portland, Ore., for example, experienced a 19 percent increase in murders in 2015 as a result of just five additional killings. Politicized voices often omit these important caveats.

The bottom line: Some cities are seeing a rise in homicides. But the country is not experiencing a national murder wave or a reversal in the long trend of decreasing crime.

We all want our families, children and police to be safe. And we all want to live in safe neighborhoods. But stoking false fear about crime will not bring or preserve “law and order.” That’s why the nation’s most prominent police and prosecutor groups, representing 30,000 law enforcement officials, wrote to Trump and Democratic nominee Hillary Clinton on the eve of the conventions to urge them to take a data-driven, modern approach to crime — one that targets violent crime while reducing the unnecessary incarceration of low-level offenders. States that have employed these practices have seen crime and incarceration fall together, which preserves resources for law enforcement.

Law enforcement isn’t the only entity that’s changed its stance on crime policy after decades of seeing what has and hasn’t worked. Many conservative leaders, including House Speaker Paul D. Ryan (R-Wis.) , New Jersey Gov. Chris Christie (R) and Newt Gingrich, agree. The Republican Party platform has also adopted a similar approach.

To be sure, as Kennedy and Abt note in their op-ed, Americans do believe that crime is rising. An April 2016 Gallup poll found that 53 percent of Americans worry “a great deal” about crime. It’s important that our country’s leaders keep the public’s concerns in mind. But stoking fear with twisted data and dangerous rhetoric doesn’t help, nor is it the best way to support our police.

If we care about law and order and changing the dire conditions in cities where violent crime is a perpetuating cycle, we need to rely on facts, not fear.