How to manage offenders within the community, especially those who have served prison sentences for serious crimes, poses a serious challenge.
If any proof were needed, it is provided by yesterday's report from the Care Inspectorate. It makes for sobering reading, revealing that at least 45 serious incidents - including 10 murders and eight sexual offences - have occurred in the last 15 months involving offenders under supervision in the community. "At least" because only 17 out of 32 local authorities provided full information to the inspectorate. The real figure is likely to be higher still.
Imprisonment provides cast-iron protection for the public from dangerous individuals. There is, quite rightly, a public expectation that those coming to the end of their sentence will be properly supervised in the community to prevent re-offending.
It is not clear from the inspectorate's report how many of these cases involved those on supervision, having been released from prison on licence, and how many were serving community sentences. What is clear is that in 45 cases, the supervision provided failed to prevent serious incidents from occurring.
It is particularly worrying that six of the eight sexual offences were committed by offenders under Multi Agency Public Protection Arrangements (Mappa) which bring together different agencies to manage risk from the most serious offenders. Clearly this did not work in these cases.
It must be said that Scotland has 23,000 offenders being supervised in the community by social work services and the vast majority are not committing serious offences.
The system can and does prevent serious crimes from occurring, as in the case of sex offender Darren Mitchell, caught by police surveillance with a 13-year-old just 16 days after being released from prison. He was re-imprisoned.
None of that will come as any consolation at all to victims and their families, however. The system has abjectly failed each and every one of those individuals.
Much work has been done in recent years on improving ways of assessing risk, but it is essential that those at risk of continuing to commit serious offences are not let out of custody under early release arrangements. As the inspectorate makes clear, every failure must be scrutinised to discern whether the case might have been better handled. It highlights a need for better working and information sharing between local authorities.
The Care Inspectorate's review of these incidents is designed to ensure lessons are learned and improve the way that offenders are supervised overall, but that cannot be done properly if only half of local authorities see fit to provide full and accurate information on such incidents. It should be mandatory. A full Scotland-wide picture of how often such incidents are occurring and in what circumstances, will help lead to better understanding of what is going wrong and how it can be prevented.
It may never be possible to eliminate the risk of serious offences by those who are on supervision, but the aim must be to try.