In almost every developed nation in the world, 12 people being killed in a mass shooting would make that incident the deadliest in years. In some nations it would be the deadliest ever. But in the United States, they happen so often, with such ferocity and carnage, that when we learn about the next one, we hardly skip a beat. Indeed, 2018 was by far the most violent year ever measured for school shootings in the United States and 2017 was the deadliest year in at least a half-century for gun deaths altogether in this country – with an astounding 40,000 people killed by guns. That’s 110 people per day. We couldn’t keep up if we tried.