AURORA VS: OCALA
Both FL and CO have concealed carry but the theater in Aurora was posted prohibiting permitted citizens to carry in the venue. The Internet Café in Ocala was not. The shooter evidenced very meticulous planning which most likely included choosing a so-called gun free venue.
Results in FL – two thugs wounded and arrested (and subsequently egregiously released on bond). Results in Aurora: 12 dead, 58 wounded. Here is a link for a paper from the University of Chicago Law School which provides convincing regressions showing that concealed carry results not only in fewer shootings but multi-victim shootings also turn out to be less severe.