Three major shootings in the span of a week has Americans on edge

41% of Americans are afraid of random mass shootings

More deadly shootings are happening even more often

A rash of mass shootings in the past week – Gilroy, California; El Paso, Texas; and now Dayton, Ohio – not only inject a new level of fear for the public but also show the phenomenon appears to be entering a new, more dangerous phase.

The number of incidents is increasing, according to data collected by researchers, and they are becoming more deadly.

And in each of the latest cases, there was very little that unsuspecting victims could have done to protect themselves.

'This is not happening again!':3 who survived Gilroy Garlic Festival shooting escaped Las Vegas in 2017

Get the latest news about Dayton:At least 9 are dead, 26 injured and the suspect is dead

El Paso tragedy still unfolding:Everything we know about the El Paso Walmart shooting

In Dayton, a gunman opened fire in the early morning hours Sunday in a popular bar and restaurant district near the city's downtown, killing nine and wounding 16. The shooting came only hours after a rifle-wielding man walked into a Walmart store in El Paso, killing 20 and wounding 26.

And both incidents follow another mass shooting last Sunday when a 19-year-old gunman cut his way through a security fence to bypass metal detectors and bag searches and opened fire at the Gilroy Garlic Festival in a farming community in California. He killed three and injuring at least a dozen before turning the gun on himself.

The Dayton gunman was also dead, but the El Paso suspect was taken into custody after the deadly rampage in the store.

A survey by Chapman University last year that found 41% of Americans fear random mass shootings.

Unfortunately, it's not an entirely unreasonable fear.

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When researchers look at public mass shootings, in which four or more people are killed by someone unrelated to them and where there are no gang or criminal connection, they see a troubling, and recent, rise.

“The evidence indicates that the severity has increased and even the incidence seems to be on the rise as well,” said Grant Duwe, research director for the Minnesota Department of Corrections in St. Paul, Minnesota.

“That wasn’t necessarily the case even two years ago after the Las Vegas attack (in which 58 people were killed). At that time the evidence indicated that the incidence of mass public shootings wasn’t on the rise,” said Duwe, a criminologist who studies trends in mass shootings.

James Alan Fox, Lipman Family Professor of Criminology, Law and Public Policy at Northeastern University, says it’s too soon to know if this increase will continue or whether it’s an anomaly. But he believes that fear on the part of the public only worsens the problem.

“Whether the rise persists isn’t certain, of course. Of concern is the level of anger, hate and feeling of being slighted that some Americans experience. The example that one way to get even with a gun is compelling for a few people. The extent that Americans are afraid plays into the mindset of the few who like to share the misery they feel — to punish society for their misfortunes,” said Fox, a member of the USA TODAY Board of Contributors.

Experts tie the rise to several factors: Would-be shooters have easy access to high-capacity firearms. The news media and social media fuel their desires for infamy. More people are willing to commit mass murder to express their anger at the world and its perceived slights.

Shooters often cite their beliefs in their postings, but experts don't blame any one ideology.

Though they often give lip service to wanting to give attention to a cause, “at its core, it’s all really personal,” said Adam Lankford, a criminology professor at the University of Alabama who studies mass shootings.

This mindset is sometimes referred to as being an "injustice collector," Lankford said.

These men — they are overwhelmingly men — often feel that they’ve been personally wronged, mistreated or overlooked, he said. Sometimes they see broader injustices they perceive as against their gender or race or religion.

“I think they’re the same thing," Lankford said. "They’re latching on to some anger that’s bigger than them.”

Heroes latch onto something bigger, too:10-year-old girl drags toddler to safety at Gilroy Garlic Festival

Killing more, more quickly

The number of victims in each incident is growing. That's true even if statisticians remove the music festival shooting in Las Vegas, where 58 died and hundreds were wounded in 2017, said Sherry Towers, a researcher at Arizona State University who has studied firearm violence.

The five deadliest public mass shootings in the USA have all occurred since 2007. From 1966 to 2009, 15% of mass shootings killed eight people or more, Lankford said. Since 2010, 30% of attacks have reached that death count.

All this has happened as crime overall has declined in the United States, said John Donohue III, a law professor and economist at Stanford University who focuses on gun control

Then what is to blame?

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In many ways, social media acts as an accelerant for the aggrieved and angry. It gives them a place to find corroboration for their frustrations and others with whom they can vent.

“Social media cannot be underestimated in the role that it plays,” Towers said. “There’s very little control of information content on social media, and that can have a significant effect, particularly on young impressionable men that may have other issues in their lives.”

In the past, shooters joined groups that motivated them to attack. Now, more are radicalized on their own while browsing the internet — "a 24-hour hate rally and bookstore," said Brian Levin, director of the Center for the Study of Hate and Extremism at California State University-San Bernardino.

The solo browsing sessions lead to "a lone-wolf mentality among the attackers. They may strike for no reason other than they are fed up,” Levin said.

These attackers also appear to be motivated in part by examples of other attacks, which some social scientists have likened to a type of contagion.

"There's a natural question about how much the El Paso shooter was influenced by attention the recent Gilroy attacker received. This may be determined after an investigation of the El Paso shooter's internet history," said Lankford.

"The El Paso shooter reportedly specifically referenced the media narratives that would follow his attack, which clearly shows he was aware of how much attention he would receive for committing a mass shooting," he said.

A kind of horrific one-upmanship

One thing that stands out to Lankford is a shift in motivations among the shooters. They increasingly seem to be motivated to kill a large number of victims to receive the most media attention, a sort of horrific one-upmanship.

“In Aurora, in his manifesto, the shooter basically ruminated on how to kill the most victims from different attack locations. The Parkland shooter wanted to kill at least 20. ... The Las Vegas perpetrator Googled ‘most crowded festivals,’ ” Lankford said.

Some of them are drawn to online forums where mass shooters are lionized. “The Sandy Hook shooter was participating and posting in these forums for three years before his attack,” Lankford said.

The internet can fuel mental health problems, allowing would-be shooters to pore over disturbing images of violence and hatred, Stanford's Donohue said.

Much of the increase in mass shooting deaths prior to this year comes from the high number of victims in the Pulse nightclub shooting in Orlando, Florida in 2016 and the Las Vegas Route 91 Harvest Festival shooting in 2017.

Some have said that those incidents should be included because they’re outliers in the overall scheme of public mass shootings.

Duwe, with the Minnesota Department of Corrections, disagrees.

“These events are statistical outliers themselves, even in the context of homicide and violent crime in general,” he said. “This is why they drive debates about what our responses should be.”

Contributing: Jared Weber