Yes, you think it would be much simpler, and much simpler doesn't give us a proper answer.
If you're making a claim, make a claim that you know. So far you're making a claim which isn't backed by anything you know.
So, they went and attacked a place in California. Did they attack because it was a "gun free zone", or did they just choose a place? Would it have made a difference had it not been a "gun free zone" or not?
Yes, you could go on and on, and you're not talking about mass shootings in non-gun free zones. Which means that what you're saying doesn't present us with a balanced picture at all.
As for me providing mass murders in non-gun free zones. Why should I? My point is that gun free zones might be places that are more likely to be shot up, hence why they become gun free zones in the first place, to reduce the instance of guns in this area.
Most of these are schools or places of education where young people are sometimes rebelling against their lives.
30 Deadliest Mass Shootings in U.S. History Fast Facts - CNN.com
But there's the 30 deadliest mass shootings.
The first two are schools.
The next one in 1991 happened in a cafeteria.
1984, 1966, 1986, 1983, 1982, 1949, 1990, 1989 and 1982 all happened before the gun free schools zone act was passed in October 1990 and effective January 1991.
1993, a law office and various others happened in places that were public.
Report: 92 Percent of Mass Shootings Since 2009 Occurred in Gun-Free Zones - Breitbart
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On October 9, the Crime Prevention Research Center (CPRC) released a revised report showing that 92% of mass public shootings between January 2009 and July 2014 took place in gun-free zones."
"The CPRC report was released in response to an Everytown for Gun Safety study claiming only 14% of mass public shootings took place in gun-free zones. "
Oh great, one report says 92% in gun free zones, another says 14%. So you believe who you will.
"CPRC showed that the 86% claim rests on Everytown’s “inclusion of attacks in private homes” and “numerous errors in identifying whether citizens can defend themselves.”"
Was the CPRC's information correct? Probably not.
What about Everytown's? Is their correct? Probably not.
There's lot of analysis of information that needs to be done. Yes, people like their simple statements that "prove" what they want to be proven, but does it actually make sense? Probably not.