The only mass shooting that the government could have prevented occurred at the Sutherland Baptist Church shooting in Texas. The killer was in trouble with the law when he was in the military, but through sloppy record keeping, that was not put on his record. As a result of that government failure, he was able to buy guns that killed 26 worshipers. So much for relying on government to protect you.
I would mostly agree with you....adding the the Stoneman Douglas School shooting. In that case, the twenty-odd visits by the police to the home...should have been flagged, and that kid by age 16 should have been taken to a full-up max security facility. The local cops had chances, and just kept saying....let’s see how far this kid can go.