I think my response would be:
Dear Sprouts Customer Relations,
Thank you very much for the prompt and considerate reply to my letter dated _____. It means a lot to me to know that retailers such as yourself are dedicated to not only your own sales but to the welfare and security of your shoppers as well. Can you provide me with details as to: 1) what, specifically, you do to provide a safe environment for your shoppers that would mitigate an active shooter scenario to provide for the safety of your patrons and 2) documentation for the 'overwhelmingly positive community feedback' that you you've received for making your stores gun free? As a person that carries a firearm for my personal safety, I'm always interested in how retail stores and other public 'gun free zones' enact measures to keep the public safe from active shooters and how the local community has recognized these efforts by the property owners.
Thanks!