What happened
In February 2026, the Dutch Justice and Security Inspectorate reported serious problems with OXREC, a tool used by probation services to estimate whether someone was likely to reoffend.
OXREC had been used since 2018 and was run around 44,000 times a year. Its assessments helped inform advice given to prosecutors, courts and the prison service. But the Inspectorate found errors in how the tool had been set up. Most significantly, the formulas for people in detention and those outside detention had been swapped.
This was not a minor technical error. The Inspectorate estimated that around 21 per cent of general reoffending assessments could have ended up in a different risk category. The mistake pushed risk estimates too high for people who were not detained and too low for those who were.
There were broader concerns too. The Inspectorate found that the model relied on outdated data collected for a different purpose and population. It also raised concerns that factors such as neighbourhood and income could contribute to indirect discrimination.
The probation organisations stopped using OXREC on 12 February 2026.
What an auditable version would have shown
The state secretary reportedly told Parliament that it was impossible to determine whether the problems with OXREC had actually changed the advice given by probation officers, or whether that advice went on to affect decisions in the criminal justice system.
Probation officers did not rely on the tool alone. They used professional judgment alongside its risk assessment. But once the problems were discovered, there was no reliable way to go back and see how much influence the OXREC score had on an individual decision.
This is where a clearer record could have helped. For each assessment, it could have shown which version of OXREC was used, what risk category it produced, and how the probation officer considered that result when forming their advice. That would not replace human judgment or reduce it to a number. It would simply leave enough of a trail to understand what happened when something went wrong.
Where the gap was
It was reported that the Inspectorate found a risk that staff would too readily adopt the tool’s outputs and stop trusting their own judgment. It was reported that the Inspectorate recorded that staff had been told their own judgment was about as reliable as tossing a coin, which the Inspectorate said overstated the reliability of the algorithm.
A ConductRecord keeps the inputs, the model version, the score and what the person advising did with it. A MetricRecord is designed to count how often a score was followed and how often it was departed from. A ConstraintGate is designed to check a standing rule, such as whether a model has been validated for the population it is being run on, before the score is used.
None of these decides what risk category a person belongs in.
What governance should have looked like
It was reported that the probation organisations paused the tool on the day the report was published and said they would take up all of the Inspectorate’s recommendations. While OXREC is paused they said they would use RISC, a non-algorithmic instrument, to support structured professional judgment, and the government said a four eyes principle or collegial review could safeguard the quality of advice meanwhile.
Where an organisation uses an automated score to inform advice to a court, best practice would be to keep the score with the advice it informed, alongside the model version that produced it and what the person advising did with it. The organisation should also be able to say which population the model was validated on, and to check that before running it on anyone else.
Failure Pattern: it was reported that a risk prediction model used in probation advice ran for eight years with the formulas for detained and non-detained people swapped, and that the state secretary told Parliament the effect on individual advice could not be reconstructed afterwards.
Governance Principle: where an organisation uses an automated score to inform a decision about a person, it should be able to show which version of the model produced the score, what went into it and what the person advising did with it.
The reference implementation of ConstraintGate, ConductRecord and MetricRecord is open source. It lives at github.com/saffronandindia/headlights-oss, Apache 2.0 licensed and free to install. The repository is public now.
Sources
- Risicovol algoritmegebruik door reclassering, the Inspectorate’s news item, carrying the figure of about 44,000 uses a year (Inspectie Justitie en Veiligheid, 12 February 2026)
- Rapport Risicovol algoritmegebruik, the report itself (Inspectie Justitie en Veiligheid, 12 February 2026)
- The state secretary’s policy response, carrying the swapped formulas, the drug parameter figures, the variables and the decision to pause (Kamerstuk 29 270, nr. 162)
- Answers to parliamentary questions, carrying the 21 per cent and 6 per cent estimates and the statement that individual effects cannot be reconstructed (Aanhangsel van de Handelingen 2025-2026, nr. 1220, received 4 March 2026)
- The probation organisations’ own statement on the measures taken and the use of RISC while OXREC is paused (Reclassering Nederland, February 2026)