Facebook founder Mark Zuckerberg has addressed the Philando Castile shooting after Castile’s girlfriend, Diamond Reynolds, live streamed the shooting to Facebook after he was shot by police during a traffic stop.

The Facebook boss called the images “graphic and heartbreaking” but acknowledged that they “shine a light” on the fears many face.The shooting of Philando Castile by a police officer in Minnesota — the second fatal police shooting of a black man by police in as many days — has caused outrage across the U.S. and reignited the debate over race and law enforcement. Much anger has stemmed from graphic footage of the shooting’s immediate aftermath, streamed live on Facebook by Castile’s girlfriend Diamond Reynolds.

In a statement posted to Facebook on Thursday, the social network’s founder Mark Zuckerberg called Reynolds’ video “heartbreaking” but recognized its role in bringing attention to the issue.