It seems that the general public is looking to disprove Obama and his dismissal of armed response to active shooters. The hot topic of the day is, “has anyone armed ever stopped a mass shooting from happening?”. While statistics will never give the entire view of what could have happened, there are multiple reports of mass shootings being stopped by law abiding citizens as reported by the Washington Post:
1. In Chicago earlier this year, an Uber driver with a concealed-carry permit “shot and wounded a gunman [Everardo Custodio] who opened fire on a crowd of people.”
2. In a Philadelphia barber shop earlier this year, Warren Edwards “opened fire on customers and barbers” after an argument. Another man with a concealed-carry permit then shot the shooter; of course it’s impossible to tell whether the shooter would have kept killing if he hadn’t been stopped, but a police captain was quoted as saying that, “I guess he [the man who shot the shooter] saved a lot of people in there.”
3. In a hospital near Philadelphia, in 2014, Richard Plotts shot and killed the psychiatric caseworker with whom he was meeting, and shot and wounded his psychiatrist, Lee Silverman. Silverman shot back, and took down Plotts. While again it’s not certain whether Plotts would have killed other people, Delaware County D.A. Jack Whelan stated that, “If the doctor did not have a firearm, (and) the doctor did not utilize the firearm, he’d be dead today, and I believe that other people in that facility would also be dead”; Yeadon Police Chief Donald Molineux similar said that he “believe[d] the doctor saved lives.” Plotts was still carrying 39 unspent rounds when he was arrested. [UPDATE: I added this item since the original post.]
4. In Plymouth, Pa., in 2012, William Allabaugh killed one man and wounded another following an argument over Allabaugh being ejected from a bar. Allabaugh then approached a bar manager and Mark Ktytor and reportedly pointed his gun at them; Ktytor, who had a concealed-carry license, then shot Allabaugh. “The video footage and the evidence reveals that Mr. Allabaugh had turned around and was reapproaching the bar. Mr. [Ktytor] then acted, taking him down. We believe that it could have been much worse that night,” Luzerne County A.D.A. Jarrett Ferentino said.
5. Near Spartanburg, S.C., in 2012, Jesse Gates went to his church armed with a shotgun and kicked in a door. But Aaron Guyton, who had a concealed-carry license, drew his gun and pointed it at Gates, and other parishioners then disarmed Gates. Note that in this instance, unlike the others, it’s possible that the criminal wasn’t planning on killing anyone, but just brought the shotgun to church and kicked in the door to draw attention to himself or vent his frustration.
6. In Winnemucca, Nev., in 2008, Ernesto Villagomez killed two people and wounded two others in a bar filled with 300 people. He was then shot and killed by a patron who was carrying a gun (and had a concealed-carry license). It’s not clear whether Villagomez would have killed more people; the killings were apparently the result of a family feud, and I could see no information on whether Villagomez had more names on his list, nor could one tell whether he would have killed more people in trying to evade capture.
7. In Colorado Springs, Colo., in 2007, Matthew Murray killed four people at a church. He was then shot several times by Jeanne Assam, a church member, volunteer security guard and former police officer (she had been dismissed by a police department 10 years before, and to my knowledge hadn’t worked as a police officer since). Murray, knocked down and badly wounded, killed himself; it is again not clear whether he would have killed more people had he not been wounded, but my guess is that he would have (UPDATE: he apparently went to the church with more than 1,000 rounds of ammunition).
8. In Edinboro, Pa., in 1998, 14-year-old Andrew Wurst shot and killed a teacher at a school dance, and shot and injured several other students. He had just left the dance hall, carrying his gun — possibly to attack more people, though the stories that I’ve seen are unclear — when he was confronted by the dance hall owner James Strand, who lived next door and kept a shotgun at home. It’s not clear whether Wurst was planning to kill others, would have gotten into a gun battle with the police, or would have otherwise killed more people had Strand not stopped him.
9. In Pearl, Miss., in 1997, 16-year-old Luke Woodham stabbed and bludgeoned to death his mother at home, then killed two students and injured seven at his high school. As he was leaving the school, he was stopped by Assistant Principal Joel Myrick, who had gone out to get a handgun from his car. I have seen sources that state that Woodham was on the way to Pearl Junior High School to continue shooting, though I couldn’t find any contemporaneous news articles that so state.