This isn't a problem that will be solved by technology anytime soon. There are more guns in the U.S. than people. Even if you had a perfect tracking system for

This isn't a problem that will be solved by technology anytime soon. There are more guns in the U.S. than people. Even if you had a perfect tracking system for legally sold weapons, there are plenty of people willing to sell guns illegally, just like there are many people willing to sell drugs illegally. A shooter can keep loaded guns in his car trunk, park in front of an establishment, and run inside in 20 seconds. It will be a long time before we have AI that can identify and subdue a gunman within 20 seconds.