In the last minutes before he was shot Tamir could not have known that he was now in grave danger. As though by magic a stranger had reached out and transformed him. Shot: An undated photo of Tamir Rice, who was killed by police. Credit:New York Times He was no longer a boy with toy in a park but a black male with a gun. According to the police when the officers arrived on the scene they instructed Tamir to put his hands up. He reached for his gun and two shots were fired, they say. Tamir did not die until early on Sunday morning. Later on in the morning CNN was having a roundtable discussion about the tension in Ferguson, Missouri, where the community fears violence might break out should a grand jury decide not to lay charges against another cop who shot dead another unarmed young black man, Michael Brown.

One of those on the CNN panel was Jim Wallis, a Christian social justice activist. There is no suggestion he had even heard of Tamir Rice when he spoke, but he could have been talking about him. "Every African American dad that I know has the talk with their son about how to deal with being in the presence of a white policeman with a gun," he said. "I am a white dad … I won't have that talk with my two white sons." It is not known what colour the Cleveland police were, though others have noted that the problem in America is not between young black men and white police, but young black men and police in general. Studies show African-Americans males are about as likely to smoke marijuana as whites, but four times more likely to be arrested for it. According to the American Civil Liberties Union, innocent New Yorkers were stopped and frisked by police four million times between 2002 and 2010, 90 per cent of them from minority communities. The impact on crime rates of the stop-and-frisk practice is contested. The fact that it has destroyed the relationship between police and minorities is not.

Washington Post columnist Eugene Robinson could have been discussing Tamir last year when he wrote, "Our society considers young black men to be dangerous, interchangeable, expendable, guilty until proven innocent. "But black boys in this country are not allowed to be children. They are assumed to be men, and to be full of menace." He wasn't of course. He was writing about Trayvon Martin, a young black man who was followed home and then shot dead by the neighbourhood watch volunteer George Zimmerman. Zimmerman was not even arrested before six weeks of protests forced authorities' hands, and later he was found not guilty of committing any crime. And in considering Tamir's killing it is impossible not to think of the shooting of John Crawford, who in September picked up a pellet gun from the shelves of a Walmart store in Beavercreek, Ohio.

Another customer called emergency services to say there was a man in the store waving a rifle about. Police arrived five minutes after the call and in seconds had shot him dead. Other witnesses – and video evidence – suggest that Crawford had simply been wandering the aisles, chatting on his phone. Neither officer has been charged. Ohio is an open carry state. Even if Crawford had been carrying a loaded rifle, it would have been perfectly legal for him to do so, just as it is for the overwhelmingly white members of Open Carry Texas, who are commonly to be found hanging around in shopping centers armed with military-style semi-automatic rifles in celebration of their right to bear arms. None of them have yet been stopped by police, let alone shot. The sense among many African-Americans that the most dangerous part of their day will be when they inevitably cross paths with a police officer now runs deep. Some are scared, others are angry, many are determined to use the protests in Ferguson as a fulcrum for change.

As the community waits to hear from the grand jury, US President Barack Obama, has called for calm. "This is a country that allows everybody to express their views. Allows them to peacefully assemble, to protest actions that they think are unjust. But using any event as an excuse for violence is contrary to rule of law and contrary to who we are," he told ABC News in an interview on Friday. He added that minorities who believe they are unfairly treated are sometime justified in that view. "Sometimes they are not." After Tamir died on Sunday a police union spokesman told the media: "We have to assume every gun is real. When we don't act, that's the day we don't come home." And this is a fair point for the representative of a public servant doing a dangerous job to make. But you can't help thinking that Tamir's family expected him home on Saturday afternoon, too.