Stanford University professor and researcher John J. Donohue suggested Wednesday that it is “much more common that an unarmed person will stop a mass shooting than an armed citizen will.”

He made his comment on the Pat Morrison Asks podcast at the Los Angeles Times, based on the observation that “most people are unarmed.”

Donohue’s suggestion can be proven wrong via logic and experience.

First, consider how it would look if one tried to present Donahue’s statement as a logical argument:

Premise A: Most people are unarmed. Premise B: Some mass shootings are stopped. Conclusion (A+B =): It is “much more common that an unarmed person will stop a mass shooting than an armed citizen will.”

It is readily apparent that Donohoe’s conclusion is actually an assertion in need of substantiation; it does not follow from the premises he used.

And that is because there are so many variables that Donohoe leaves out. Those variables include Democrat-mandated gun-free zones, where law-abiding Americans who are normally armed for self-defense are forced into the category of “unarmed” persons by forces outside their control. The variables also include an unstated, or unknown, percentage of mass shootings that are actually stopped by unarmed people.

When testing Donohue’s claims in light of experience, the problems with his claims are even clearer. It is almost always a “good guy or girl with a gun” who stops a public mass attacker.

The second-most-probable outcome is that the attacker takes his or her own life.

Consider the following mass public attacks:

the Orlando attacker (June 12, 2016) was killed by good guys with guns.

the UCLA gunman (June 1, 2016) killed himself.

the San Bernardino attackers (December 2, 2015) were killed by good guys with guns.

the Colorado Springs attacker (October 31, 2015) was killed by good guys with guns.

the Umpqua Community College attacker (October 1, 2015) killed himself after being shot by good guys with guns.

Alison Parker’s attacker (August 26, 2015) killed himself after being chased by good guys with guns.

the Lafayette movie theater attacker (July 23, 2015) killed himself.

the Muhammad Carton Contest attackers (May 3, 2014) were killed by a good guy with a gun.

the Las Vegas cop killers (June 9, 2015), one of whom committed suicide and one whom was killed by good guys with guns.

the Santa Barbara attacker (May 23, 2014) killed himself after being confronted by good guys with guns.

the Fort Hood attacker (April 2, 2014) was wounded and arrested after being shot by a good guy with a guns.

the Arapahoe High School attacker (December 13, 2013) killed himself after being confronted by a good guy with a gun.

the D.C. Navy Yard attacker (September 16, 2013) was killed by good guys with guns.

the Aurora movie theater attacker (July 20, 2012) was arrested by good guys with guns minutes after the attack began.

the Fort Hood attacker (November 5, 2009) was shot and stopped by good guys with guns.

the Virginia Tech attacker (April 16, 2007) killed himself.

The claim that it is “much more common that an unarmed person will stop a mass shooting than an armed citizen will” is demonstrably false.

AWR Hawkins is the Second Amendment columnist for Breitbart News and host of Bullets with AWR Hawkins, a Breitbart News podcast. He is also the political analyst for Armed American Radio. Follow him on Twitter: @AWRHawkins. Reach him directly at awrhawkins@breitbart.com.