Why is it that so many news articles and opinion pieces indicate that there are hundreds of mass shootings each year in the United States, and then go on to cite only examples of mass killings? Do they want to create mass hysteria?

The hundreds of episodes contained in the Gun Violence Archive are frequently invoked to try to characterize a horrific thing (such as the El Paso and Dayton massacres) as commonplace, happening at an alarming rate of about one a day. But by their definition of mass shootings (four or more victims shot), only one-quarter involve multiple fatalities and only 7 percent reach the threshold of a mass killing (at least four victim fatalities). The mass shootings listed in the Gun Violence Archive involve an average of just over one fatality, which sometimes includes the assailant.

According to the mass-killing database compiled by the Associated Press, USA Today, and Northeastern University, there are about two-dozen mass shootings each year in which four or more victims are killed. Other than a spike in mass killings in public spaces over the past couple of years, the incidence has remained relatively flat since at least the mid-2000s.

Of course, shootings resulting in a large number of injuries are not inconsequential, and it is worthwhile that these data have been tracked since 2013. However, they should not be confused with shooting sprees in which large numbers of victims lose their lives. It is like mixing data on highway accidents with figures on highway deaths.

In this climate of fear, where active shooters are seen as the modern-day boogeyman, imprecise reporting can easily mislead the public, inadvertently creating panic and prompting poorly conceived policy responses. A headline this week in a California daily, for example, asserted that mass shootings had nearly tripled since 2000, resting on the authority of FBI research.

That FBI research, however, concerned active-shooter events in which a gunman had designs on killing large numbers of people, whether or not successful. In fact, most of the time, the shooters failed to realize their goal. In one-quarter of these episodes, no one was killed, and sometimes no one was even injured. Last year, word spread like rapid-fire when an active shooter was reported at YouTube headquarters in San Bruno, Calif. By the time the satellite trucks and television helicopters had left the scene and cable news channels had turned to other issues of the day, the only one killed was the 38-year-old assailant, by her own hand.

More important, the evidence of an increase that has been cited countless times is deeply flawed by the inability of finding older cases through open-source news searches. For example, the FBI data indicate that back in 2000, there was but one person in the entire United States who picked up a gun with the intention of slaughtering innocents. Only one? This is hardly plausible in a population that was then nearly 300 million people, with more than 300 million guns. More likely, those low-level cases with limited casualties were never reported in newspapers, nor were there social media sites to spread the word.

As evidence that the trend is little more than a function of data recall, consider the change in the FBI’s nonfatal active-shooter events. From 2000 through 2003, where the data were gathered retrospectively, 9 percent of active shooters killed no one. From 2014 through 2017, where the cases were being identified as they occurred, aided by the wealth of online news outlets and social media, 27 percent of active shooters failed to kill anyone. Either active shooters of recent vintage are not nearly as skilled in marksmanship as their predecessors, or the FBI data collection efforts were not able to find many of the nonfatal episodes going way back in time.

Without a doubt, massacres like those that took place in El Paso and Dayton earlier this month are tragic, having wide-ranging impacts in terms of the nation’s collective sense of safety and security. Although rare, such large-scale mass killings are terrifying, since they can happen to anyone, at any time, and at any place. It is important, however, not to push those fears beyond reasonable limits by associating these extreme and heavily covered events with data claims based on incidents of a very different nature.

James Alan Fox is a professor of criminology, law, and public policy at Northeastern University and coauthor of “Extreme Killing: Understanding Serial and Mass Murder.’’