The slaying of two journalists Wednesday as they broadcast live to a television audience in Virginia is still seared on our screens and our minds, but it’s a moment not only to mourn but also to learn lessons.

The horror isn’t just one macabre double-murder, but the unrelenting toll of gun violence that claims one life every 16 minutes on average in the United States. Three quick data points:

■ More Americans die in gun homicides and suicides every six months than have died in the last 25 years in every terrorist attack and the wars in Afghanistan and Iraq combined.Read more »