The day before we spoke, King 1 , 26, had learned that his friend Lamont had been killed. He was at home when his cousin called to break the news and asked him to come over. ‘I’m on my way,’ King replied immediately, knowing what was being asked of him. He ran up to his room to retrieve his Glock, opened his box of bullets and, one by one, filled the clip.

Lamont was dead, though King couldn’t fully wrap his mind around the fact. He’d seen him only hours earlier, when Lamont and King’s cousin stopped by his house. They’d been shot at by their rivals the day before, and King had warned them to be careful: ‘Y’all need to keep y’alls’ heads up.’ Now the car Lamont died in sat empty on a nearby street, shot up and stained with his blood. King watched a video posted on Facebook of paramedics draping the body with a sheet and carrying it into an ambulance.

King knew what came next. He and his cousin would go out with their guns and ride through the neighbourhood until they found the men responsible.…