Donald Trump has spoken. He has described the Las Vegas slaughter as an act of pure evil. That may be so, but it was also an act of utter banality. We have been here before.

An angry American man shot dead innocents en masse and then turned a gun on himself.

Sean Bolger is comforted by a friend during a vigil for the people killed in Las Vegas. Credit:AP

Only the details differ. The shooter in this case is older than usual and the toll of dead and wounded higher. The video from the scene suggests that on this occasion the murderer might have used a fully automatic weapon rather than a semi.

We don't yet know if the guns were legally acquired, but what is staggering – to those outside the United States at least – is that they may well have been.