Cinema Shooting, Theatre was "gun free zone"

I don't have time to write too much more, but apparently Cinemark (the parent company) has a no guns policy.

Cinemark has No Guns Policy

John Lott likewise has confirmed this.

Private business owners who invite the public onto their own premises can set their own policies: “Nothing in this part 2 [establishing the scope and limits of a Colorado concealed carry permit] shall be construed to limit, restrict, or prohibit in any manner the existing rights of a private property owner, private tenant, private employer, or private business entity.” Colo. Rev. Stat. Ann. § 18-12-214(5). Source.