These revelations undermine two arguments in the debate around gun control. Some gun-control advocates contend only the police should carry firearms — but a hesitant, risk-averse police force that moves at a glacial pace while children are bleeding to death provides little protection for anyone. Scot Peterson, the cop assigned to Marjory Stoneman Douglas High School in Parkland, Fla., who did not engage the school shooter, no longer appears to be a one-off.

Second Amendment supporters often counter, “The only thing that stops a bad guy with a gun is a good guy with a gun.” Except the hallway of Robb Elementary School had no shortage of good guys with guns, and yet they did not stop the massacre until it was far too late.

Perhaps that slogan should be revised, “The only thing that stops a bad guy with a gun is a good guy with a gun and the willingness to act.” No Uvalde cops acted when it could have made a difference.