The horror shows of mass shootings transfix the nation, and this long hot summer started at the end of spring with slaughters at a supermarket in Buffalo, New York, and at an elementary school in Uvalde, Texas.

The July 4 massacre in Highland Park, Illinois, put an exclamation point on a season where multiple shootings have grabbed the headlines.

And then, there are the tragedies that law enforcement agencies have thwarted.

Dogwood Dell in Richmond, a performance venue in Byrd Park, was reportedly the target on July 4. Two bands and a fireworks show put on a free show in peace … because police had received a tip of a planned mass shooting there, and took action to prevent it.

Richmond’s police said two men have been arrested, and two assault rifles and ammunition were found, in connection with the planned attack.

It’s abundantly clear, although no one wants to believe it, that it can happen here. Virginia has suffered two horrible mass shootings: Virginia Tech in 2007 a...