Until I watch the prisoners line up alongside the chains laid out on the ground, I have half imagined that the term 'chain gang’ is being used in a loose and euphemistic way.

But no. They are wearing heavy-duty work boots and, as the chains are padlocked around their ankles, they raise their left legs up behind them, bending at the knees like well-trained horses obliging a farrier.

What makes this scene even more disturbing is the sex of the prisoners. They are all women.

This is Arizona, America’s most draconian state. It is also its hottest, averaging around 40°C in the summer, which makes the concept of hard labour outdoors seem all the more cruel.