In the wake of the mass shooting at a community college in Oregon, Democratic National Committee chairwoman Debbie Wasserman Schultz said that the "national epidemic" of such incidents demands a response from Congress.

She directed some of her criticism at former Gov. Jeb Bush -- one of the Republican presidential candidates from her home state of Florida:

"A message for Jeb Bush: 380 Americans have been killed in 294 mass shootings in 2015 alone. ‘Stuff’ doesn't just ‘happen.’ Inaction happens," she said in an Oct. 2 tweet . (Here’s the background of what Bush said.)

A reader asked PolitiFact to look at her statistical claim, because if you divide victims by shootings, then the numbers suggest that there are less than two deaths per "mass" shooting.

We found that Wasserman Schultz used an overly broad definition of what most people would consider a mass shooting.

A look at the statistics

Wasserman Schultz’s spokesman said she was citing a report in the Washington Post’s Wonkblog, which stated that the Oregon shooting brought the total of mass shootings this year to 294.

The statistic came from Mass Shooting Tracker , a crowdsourced site, which defines mass shooting as any in which four or more people are shot, regardless of whether they die or are injured. But that definition is more broad than some other definitions, which we will get into later.

Mass Shooting Tracker showed 294 mass shootings as of Oct. 1. About 122 of those incidents -- or about 42 percent -- involved zero fatalities. The shootings killed 379 people and injured 1,094.

Brock Weller, a Portland, Ore., resident who launched the website in 2013, told PolitiFact he gets his information from news reports. Weller said he supports more gun control "but the site is just data and is no more political than a phone book."

While the website defines mass shootings to include fatalities and injuries, a key federal government report defined "mass shooting" and "mass murder" as four or more fatalities.

The federal government’s more restrictive definition means it tends to count fewer incidents than Mass Shooting Tracker. Using 2013, the most recent year for which federal data is available, the Congressional Research Service found 25 mass shooting incidents -- far less than the 363 counted by Mass Shooting Tracker.

We looked for 2015 data for the federal definition of mass shootings, but it isn’t yet available. Based on its definitions, we would expect the total to be significantly lower than Mass Shooting Tracker, but we can’t say by how much.

USA Today has been tracking the data and found approximately 18 mass killings by firearms so far in 2015.

A spokesman for Wasserman Schultz defended her use of a broad definition of mass shooting.

"I think the main point is that mass shootings that result in both deaths and injuries are occurring too frequently in this country," spokesman Sean Bartlett said. "And it’s both reasonable and publicly understood that a mass shooting does not necessarily have to require a minimum amount of deaths, because the intent of the shooter is to kill and instill fear. Regardless of the outcome of a shooting, there are still serious physical and psychological effects."

Experts’ caveats

An academic told us that one problem with Mass Shooting Tracker is it lumps together incidents that are different -- for example, those shot in bar fights are counted along with school shootings.

"This is not consistent with the motivations behind events like Columbine, Virginia Tech, Aurora, Tucson, or Sandy Hook, and therefore are not comparable in the way we think of mass shootings," said Jaclyn Schildkraut, at State University of New York System. "By including such events to try and quantify a phenomenon (though the loss of one life is one too many), these sources essentially are inflating the statistics."

Northeastern University professor James Alan Fox said it’s the fatal shootings that draw the most attention.

"If six people are shot and they survive, it has nowhere near the impact as six people killed. ...It’s qualitatively different," he said.

Politicians or others who want to make a point about guns choose a set of data and a definition that reinforces the point they want to make. People who want more gun control tend to choose more expansive definitions.

"Those who want to create a sense of crisis over the violence will tend to use lower cutoffs, while those who want to minimize the problem will use higher cutoffs," said Gary Kleck, a criminology professor at Florida State University.

Our ruling

Wasserman Schultz said, "380 Americans have been killed in 294 mass shootings in 2015 alone."

She cited the crowdsourcing site Mass Shooting Tracker, which showed 379 people killed in 296 mass shootings.

But Mass Shooting Tracker uses an extremely broad definition of what many people would consider a mass shooting. If she had used a more restrictive definition that only counts incidents with deaths, as the federal government does, she would have come up with a much lower number. The Congressional Research Service counted 25 incidents in 2013, compared with 363 incidents counted by Mass Shooting Tracker.

The claim is partially accurate but takes things out of context. We rate this claim Half True.