The term ‘diversion’ describes a process of decision-making that results in offenders with mental health issues being redirected away from the criminal justice system and into the health and social care sectors. This may happen at any stage of the criminal justice process: before arrest, after proceedings have been initiated, in place of prosecution, or when a case is being considered by the courts.

If a prosecution is begun, the Crown Prosecution Service (CPS) might decide to halt it. Alternatively, if the offender is prosecuted because prosecution is appropriate, the courts might opt for a relevant disposal under the Mental Health Act 1983 – such as a hospital order – rather than a criminal justice disposal, such as imprisonment.

Diversion aims to ensure that, where possible, offenders with mental health issues are referred to health services, social services and voluntary sector organisations for support and treatment, rather than being punished via prosecution and prison custody. As a policy, diversion has been consistently reiterated by government ministers and backed up by guidance in the form of Home Office Circulars 66/90 ‘Provision for Mentally Disordered Offenders’ and 12/95 ‘Mentally disordered offenders: Inter-agency working’.

Diversion is not the same thing as discontinuance, which describes a situation where the CPS decides not to continue a prosecution. This is possible because although criminal proceedings are initiated by the police, the decision whether to proceed with a prosecution lies with the CPS. The CPS will weigh up various factors in determining whether to continue with a prosecution. In some cases it may decide not to do so.