It’s an eerie thought, but the streets of downtown D.C. are always listening for gunfire. A system of microphones called ShotSpotter blankets 17 square miles of the city, and it can triangulate the source of a fired gun with incredible accuracy.

On its own, that resulting map is a somewhat impersonal, helicopter view of violence. But when neighborhood schools are plotted in the mix? It’s a chilling call to action.

See the interactive map here





Nancy La Vigne, director of the Urban Institute’s Justice Policy Center, partnered with colleague Sam Bieler to cross reference ShotSpotter data with the locations of inner city D.C. schools. They threw out all of the gunshots that occurred outside the bounds of 7 a.m. and 7 p.m., as well as holidays and half days, so that they could paint a clearer picture of the shots children can actually hear when school was actually in session.

What they found was that during the 2011-2012 school year, of the 336 gunshots tracked by ShotSpotter during these hours, 54% occurred within 1,000 feet of a school–which made them loud enough to be heard indoors (you can listen for yourself here). As that played out, students in 54% of schools across the city (or 95 schools total, we believe) heard gunfire at least once through the year.

On the Urban Institute’s map, the gunfire is depicted as yellow orbs, and the schools are represented by pins similar to what you’d see in Google Maps. Schools in blue were more than 1,000 feet from any gunshot through the year. Schools in pink were within 1,000 feet. And schools depicted in black were within 500 feet–a distance at which gunfire sounds perfectly clear, close, and visceral.

As you might expect, the schools linked by their proximity to shootings were also clustered together geographically. Blue schools are generally surrounded by other blue schools, pink by pink, and black by black. But what you don’t see in this visualization is that just 9% of the schools experienced 48% of the total gunfire through the year.

The project’s researchers say more study is needed to determine the exact effects of audible gunfire on the growing mind, and how these acts of violence impact class attendance.