This has certainly been discussed before, but I took the time to lay things out and group the various shootins based on whether people could/would carry handguns or not.
For this purpose I'm using "mass shooting" to mean any incident where 4 or more people are killed in a single event. This is what I could find. If I've missed any, let me know.
Incidents where shooter(s) knew that no law abiding citizens carried handguns:
Date Location City State Number killed
Aug 66 University of Texas Austin TX 15
Oct 91 Luby's Cafeteria Killeen TX 23
Arp 99 Columbine Littleton CO 12
Mar 05 Red Lake high school Red Lake MN 7
Jan 06 Post office Goleta CA 7
Apr 07 Virginia Tech Blacksburg VA 33
Dec 07 Shopping Mall Omaha NE 8
Feb 08 Clothing store Chicago IL 5
Feb 08 Northern Illinois U DeKalb IL 5
Total killed: 115
Incidents where the shooter(s) had cause to believe that law abiding citizens carrying handguns was unlikely.
Date Location City State Number killed
Jul 83 Law office San Francisco CA 8
Jul 84 McDonalds San Diego CA 21
Feb 88 Laboratory Sunnyvale CA 7
Dec 93 LIRR Long Island NY 6
Mar 06 Party Seattle Wa 6
Total killed: 48
Note: In both California and New York handgun permits are possible, but nearly impossible for "ordinary" folk to get, thus a criminal runs little risk of running into an armed citizen. Although Washington was a "Shall Issue" state at the time of this last shooting the shooter attended the party for 3 hours and could well have assessed the likelihood whether any of the other people were armed.
Incidents where the shooter(s) ran the risk of running into individuals carrying concealed handguns
Date Location City State Number killed
Feb 83 Wah Mee club Seattle WA 14
Dec 07 Church Colorado Springs CO 4
Total Killed: 18
Note that the Wah Mee Club involved three shooters and was an organized crime "hit." This may actually belong int he previous section (had cause to believe....) The Church shooting, it is important to note, was actually stopped by a person on the scene with a handgun.
Summary:
No chance of armed citizens: 118 dead.
Armed citizens highly unlikely: 48 dead
Armed citizens more likely: 18 dead.
Looked at another way:
Rights of citizens to have the tools to defend themselves severely restricted: 166 dead.
Citizens able to have tools to defend themselves if they wish ("shall issue"): 18 dead
Conclusion: having armed citizens saves lives.
For this purpose I'm using "mass shooting" to mean any incident where 4 or more people are killed in a single event. This is what I could find. If I've missed any, let me know.
Incidents where shooter(s) knew that no law abiding citizens carried handguns:
Date Location City State Number killed
Aug 66 University of Texas Austin TX 15
Oct 91 Luby's Cafeteria Killeen TX 23
Arp 99 Columbine Littleton CO 12
Mar 05 Red Lake high school Red Lake MN 7
Jan 06 Post office Goleta CA 7
Apr 07 Virginia Tech Blacksburg VA 33
Dec 07 Shopping Mall Omaha NE 8
Feb 08 Clothing store Chicago IL 5
Feb 08 Northern Illinois U DeKalb IL 5
Total killed: 115
Incidents where the shooter(s) had cause to believe that law abiding citizens carrying handguns was unlikely.
Date Location City State Number killed
Jul 83 Law office San Francisco CA 8
Jul 84 McDonalds San Diego CA 21
Feb 88 Laboratory Sunnyvale CA 7
Dec 93 LIRR Long Island NY 6
Mar 06 Party Seattle Wa 6
Total killed: 48
Note: In both California and New York handgun permits are possible, but nearly impossible for "ordinary" folk to get, thus a criminal runs little risk of running into an armed citizen. Although Washington was a "Shall Issue" state at the time of this last shooting the shooter attended the party for 3 hours and could well have assessed the likelihood whether any of the other people were armed.
Incidents where the shooter(s) ran the risk of running into individuals carrying concealed handguns
Date Location City State Number killed
Feb 83 Wah Mee club Seattle WA 14
Dec 07 Church Colorado Springs CO 4
Total Killed: 18
Note that the Wah Mee Club involved three shooters and was an organized crime "hit." This may actually belong int he previous section (had cause to believe....) The Church shooting, it is important to note, was actually stopped by a person on the scene with a handgun.
Summary:
No chance of armed citizens: 118 dead.
Armed citizens highly unlikely: 48 dead
Armed citizens more likely: 18 dead.
Looked at another way:
Rights of citizens to have the tools to defend themselves severely restricted: 166 dead.
Citizens able to have tools to defend themselves if they wish ("shall issue"): 18 dead
Conclusion: having armed citizens saves lives.