//Up to a third recidivism, for violent crime only. Either the justice system isn't working, or the prisons. Or both.//
The overall incidence of recidivism is higher than that. But there is, of course, another explanation.
To be sent to prison in the UK the offender usually must have either committed a lengthy series of more minor offences or one of such gravity that an immediate prison sentence is the only suitable punishment. The UK is said to have a high per capita prison population compared to many other European countries and that’s certainly true. However, that is not because the UK’s justice system sends people to prison too readily. In fact quite the opposite is true when making many comparisons. As an example, if you assault a police officer in most European countries you will almost certainly go to prison, even if you are a first time offender. If you do the same in the UK you almost certainly will not, even if you have a criminal record.
By the time most petty criminals are eventually sent to prison they have usually committed a large number of offences. That is, when the time comes for their first custodial sentence they are already entrenched criminals. When the all the other disposals have been tried and failed, prison is the only realistic sanction left. It is also the only sanction which requires no co-operation from the offender. So these people end up in custody not because the justice system or prisons have failed them. They end up there because they are criminals. They continually offend and they will continue to do so until they are forcibly stopped (and prison is the only way to ensure that). In short, the UK has a higher per capita prison population than similar countries because it is home to a greater number of criminals. The criminals add to the prison population, the prisons and justice system do not add to the number of criminals.
//"...Our job is to determine if someone is safe to release. We do that with great care, and public safety is our number one priority...”//
And of course the parole board has a superb record of ensuring public safety.