Use object identification to prevent mass shooting?

The recent shooting tragedy in Florida made me wonder how applicable it is to add some AI to surveillance camera systems, to set off alarm when someone holding a handgun or rifle is detected. Here I would like to discuss these two aspects:
1 is there anything similar to this developed or in process?
2 if not, how applicable is this idea? What would be the most difficult part of developing a model like this?

I personally feel the most core part would be an image binary classification model, which should be not too hard to train and get good performance. I would love to know what you all think. Thanks!

I like the idea… however, I’m not sure if police officers or security people on campus are allowed to carry firearms… you wouldn’t want those to trigger a ton of false alarms… but I guess that could be solved by also detecting police and security people and disregarding any firearms found on them.

You are right… That adds a little more complexity…