Alton Sterling was pinned to the asphalt by two white cops in Baton Rouge, and shot four times point blank. According to The Counted, a database maintained by The Guardian, this makes him the 558th person killed by cops in the U.S. in 2016.

To those white people who often write us to ask, “What can I do?” we offer a simple suggestion: Next time you see a Black person stopped by cops, pull over, take out your phone, and bear witness.