We still don’t know why he did it. That’s one unique feature of America’s deadliest single-shooter rampage. Another is the gunman’s long distance from the 58 people he killed, meaning shooting back couldn’t help. Yet another was his use of a “bump stock,” which rigs semi-automatic firearms to fire rapidly — like fully automatic guns civilians can’t legally obtain. Now, in a rare concession amid national outrage, the National Rifle Association has given Congress its blessing to regulate the devices, while a city and nation bury their dead.