Another day, another prison riot. This time it’s at The Mount, a perfectly ordinary 30-year-old prison on the outskirts of London—not some Victorian hell hole waiting for the bulldozers to move in. And this the week after another set of statistics showing accelerating violence, self-harm and death in our prison system. The coruscating annual report of Her Majesty’s Chief Inspector of Prisons feels like a distant memory only three weeks after it was headline news.

So does the riot at The Mount tell us anything we don’t already know, and might just be bored of being told?

It will certainly have raised eyebrows in the prison service hierarchy and will be giving some Governors a sleepless night. Because prisons like The Mount aren’t supposed to cause this kind of difficulty. Its last inspection in 2015 was pretty good, and for the London prisoners facing a transfer away from the capital to serve a longish sentence, The Mount would normally be seen as one of the better options.

The Mount is a bigger place than it used to be—part of the government’s “solution” of increasing prison capacity. It has 250 more beds that it used to, and money to recruit the staff to match. But of course it doesn’t have the staff, and though the beds are slept in, the education and work facilities will be underused because prisoners are locked up for too long. A prison that could and should deliver what the government wants is just the latest victim of a system that is under more pressure than it can handle.

Governments of the last two decades have built 15 new prisons, not to mention countless new house blocks on existing sites. There is nothing in the least bit new or innovative about a prison reform programme based on new for old buildings and extra staff. But throughout those decades of expansion, the rate of overcrowding has not changed a whit—25% of prisoners in the system have been sharing cells they shouldn’t for the whole of that period. Above all, we continue to use prison out of exasperation with persistent and low level offending—of the 68,000 people sent to prison last year, around three quarters had committed a non-violent offence, and nearly half were sentenced to less than six months—a maximum of 12 weeks inside.

It simply isn’t controversial anymore to state that the prison population will always expand to fill 25% more than the available space. We have over 20 years’ experience of building more cells to prove it. But there is an experiment taking place very close to home that tries a different approach. The Scottish Government has consulted on whether to extend an existing statutory presumption against short periods of imprisonment from sentences of three months to sentences of 12 months.

This is what one commentator had to say about that this week:

“It sounds terrifying, unfair, downright soft. But the figures show that phasing out short sentences works.

“Crime is down. Reoffending is down. The endless revolving door, churning offenders in and out of Scotland’s jails, is slowing.

“Prison works. But it works best when the punishment is reserved for those who threaten public safety, those who most deserve it.

“And the expertise of those who are most skilled in reforming prisoners and changing lives should go to those who need it most.”

Not the Prison Reform Trust or the Howard League, but the Scottish Sun. And here’s what its English equivalent opined in an editorial last week:

“The fact that half our prisons are of “serious concern” or “concern” is not the fault of the new Justice Secretary, David Lidington. But fixing them falls to him...He must question why we hold so many lags who are no danger to anyone on the outside.”

It has become a truism that the politics of sentencing practice are just too difficult to embark upon. We accept this even though everyone with a close knowledge of the system quickly concludes that sending persistent and low-level offenders to prison is both pointless and fundamentally undermines the prison system’s ability to deliver real reform for the very serious offenders for whom it should be reserved. The national shame of a prison system now so far from the standards of a civilised country should prompt the Justice Secretary for England and Wales to reassess that craven assumption on public attitudes towards sentencing. One of his predecessors, Mr Gove, made much of a visit to Texas to see de-carceration in action—a short flight to Edinburgh might be both cheaper and more instructive.