As Minneapolis police investigate the appalling killing of 3-year-old Terrell Lamont Mayes Jr. from a stray bullet that apparently traveled from an alley, across two streets and through a wall, a police spokesman described how the city's high-tech "ShotSpotter" sensors picked up the gunfire. Every week police put out a "shots fired" map showing the location of shots picked up by the sensors, those called in by citizens and places where those shots actually hit someone. It's a valuable public service to put out this public information, but the sheer number of red circles is a sad commentary on the dangerous state of some Minneapolis neighborhoods. The map for the most recent week is below.

Caveats, from public safety reporter Matt McKinney: Some of the red dots may be duplicates if multiple people report the same gunshot. Some of the reports may mistake fireworks or car backfiring for shots. The dots with the black centers are more likely to be gunshots, given that they're confirmed by ShotSpotter, but that system isn't foolproof either. 

Shots Fired