Latest outputs from Data First are available to provide insight into the probation and criminal justice system

Both datasets are available via the Office for National Statistics (ONS) Secure Research Service. To enable accredited researchers to make the best of use of this data to improve our understanding of justice-system use, the datasets are supported by a suite of materials. These resources include a Data First user guide and data catalogues which describe the nature and the quality of the data shared.

Data First is a ground-breaking three-year data linking programme, led by the Ministry of Justice (MoJ) and funded by ADR UK. The project aims to unlock the potential of the wealth of data already held by MoJ, linking administrative datasets from across the justice system and beyond to better inform policy related to crime and justice.

This latest output follows the release of the Family Court dataset, which was made available in the ONS Secure Research Service in October 2021 for accredited researchers to apply to use.

About the data

The probation dataset provides data on service users (offenders), offences, disposals, community order requirements, licence conditions and post-sentence supervision requirements. It is extracted from nDelius, a system used for the management of offenders subject to probation supervision, covering records with a referral date from 1 January 2014 until 31 December 2020.

The dataset has been de-duplicated, which means multiple records of the same offender within nDelius with a referral date between 1 January 2014 and 31 December 2020 are identified and assigned a single unique identifier. This enables researchers to reliably investigate offenders who are in repeat contact with the Probation Service for multiple offences at scale, while ensuring data remains de-identified.

The new probation dataset, in addition to existing and future outputs from Data First, will help researchers better understand end-to-end experiences of justice system users. This will provide further evidence to underpin the development of government policies and drive real progress in tackling social and justice issues.

The probation dataset has been linked to other Data First products, including magistrates’ courtCrown Court and prison datasets. This ‘probation and criminal justice system linking dataset’ acts as a lookup to identify where records in the various datasets refer to the same people.

This linking dataset enables records to be grouped by individuals and repeat appearances across the criminal justice system to be investigated. This has the potential to provide new insights on end-to-end user journeys across the criminal justice system, including how offenders interact between key justice services.

How to access the dataset

Researchers seeking to securely access any of the datasets produced by the Data First programme must first become an accredited researcher by completing the relevant forms from the UK Statistics Authority and submitting them to

If you are already an accredited researcher, you can apply to access the specific data required for your project on

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