Video Surveillance is one solution. RFID and/or dynamic QR codes could be safer for the admins

In fact, without those policies and procedures in place, having video surveillance could actually be a liability for a school, says Dorn.

. . . For instance, a parent could use video footage to sue the school district for negligence if proper safety procedures are not being followed, he says.

. . . “There are a lot of things that you can do that don’t cost very much that have a greater return than cameras would normally give you,” he says, such as providing formal training in proper supervision and space-management techniques for faculty and staff members.

RIFD cards and dynamic QR codes isn't on the radar of the schools. That sounds like an opportunity for some printer.

The problem with video is that it can be wind up in court. Nobody wants to wind up in court. On the other hand, “There are a lot of things that you can do that don’t cost very much that have a greater return than cameras would normally give you, says Dorn.

"providing formal training in proper supervision and space-management techniques for faculty and staff members" is ok. Putting a scanner in the hand of every adult a clickable ID card in the hands of every student would probably be even better.

Dynamic QR codes are the game changer.

Use case:
"Stop that fighting in the halls."
" Yes, ma'am."
"Let's see your ID cards."
Click.

Mom gets an SMS in a couple of minutes.
"At 12;35 am, Johnny was fighting in the halls. Please talk to him when he gets home to see if there is a problem we need to know about. Thank you."

That leads to less fighting going forward.
No more fighting leads to kids paying attention which leads to better results in high school ed and to alot more security in the halls.

Education Week's Digital Directions:
The Digital Evolution of Video Surveillance:

Just a few years ago, David Vignery, the director of technology for the Harrisonville school district in Missouri, had to drive to the district’s six schools if he wanted to view video-surveillance footage from each building. It could be weeks before school officials alerted his team that cameras were broken or otherwise not working properly.

Now, because of technological improvements in the video-surveillance industry, it takes just a few seconds for Vignery to view any camera in the district from his desktop computer and be alerted immediately about technical problems. “It’s allowed us to utilize our time more efficiently,” he says of the new setup."