Lankford said the top five deadliest shootings have been Las Vegas, Orlando, Virginia Tech, Sandy Hook and Sutherland Springs.
He pointed out three of the five shootings have occurred in the past 1 1/2 years, with the Sutherland Springs church shooting taking place less than six weeks after the massacre in Las Vegas.
To find out why America is the leader in that dubious regard, Lankford said he studied public mass shooters between 1966 to 2012, as well as homicide and suicide rates, firearms ownership and national wealth.
"By far, the reason we have the most public mass shooters is because we have the most firearms. We had almost double the number of firearms per capita, more than any other country," Lankford said. "Contrary to what many in the U.S. say about mental illness being the root of the problem, we're No. 1 in public mass shooters, but we're nowhere near the top in terms of mental health problems or suicides."
Lankford said although the suicide rate has reached a 30-year high, America ranks 48th worldwide.
"Countries with higher suicide rates should have more public mass shooters than we do," he said.
Lankford said what is notable about the Sutherland Springs shooter is that he considered the man who gunned down members of a Sunday school class in Charleston, South Carolina, in 2015, "a role model. He specifically said, according to a co-worker, that it was 'cool' that the Charleston shooter was in the news and he wished he had the nerve to do something like that."
Lankford said that's an example of why he strongly advocates not reporting the name of any mass shooter.
Lankford is in San Antonio to serve as the keynote speaker at a conference on "Detecting Motives and Attack Intentions Among Mass Shooters and Suicide Terrorists in the U.S."
The conference is being held by the National Behavioral Intervention Team Association.
Lankford said it was scheduled before the mass shooting in Sutherland Springs occurred.
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