In April, in North Charleston, South Carolina, Officer Michael Slager was recorded coolly unloading eight bullets into the back of Walter Scott. Soon after, Baltimore erupted in protest over the death of Freddie Gray. And last month, the news came that the Madison, WI officer who killed Tony Robinson Jr would not face any charges.

These are just the latest in a spate of high-profile police killings over the last year in the United States, only a few prominent instances of the on average 928 people killed annually by US police, over the last eight years.

There is a certain tendency to see such deaths as further confirmation of a violent America, in contrast to a peaceful Europe. Holders of this view heaped praise on the Swedish cops who broke up a fight between two men on the New York City subway in April, and circulated the claim that the US’s 111 police killings in March more than doubled the figure in Britain since 1900. What force is exerted by police in the Old World is perceived to be minimal and all the more effective for it.