Mass shootings involving AR-15s have become a recurring American nightmare.

The weapon, easy to operate and widely available, is now used more than any other in the country’s deadliest mass killings.

Fired by the dozens or hundreds in rapid succession, bullets from AR-15s have blasted through classroom doors and walls. They have shredded theater seats and splintered wooden church pews. They have mangled human bodies and, in a matter of seconds, shattered the lives of people attending a concert, shopping on a Saturday afternoon, going out with friends and family, working in their offices and worshiping at church and synagogue. They have killed first-graders, teenagers, mothers, fathers and grandparents.

But the full effects of the AR-15’s destructive force are rarely seen in public.

The impact is often shielded by laws and court rulings that keep crime scene photos and records secret. Journalists do not typically have access to the sites of shootings to document […]