Forensic social work is the application of social work to questions and issues relating to law and legal systems. This specialty of the social work profession goes far beyond clinics and psychiatric hospitals for criminal defendants being evaluated and treated on issues of competency and responsibility. A broader definition includes social work practice which in any way is related to legal issues and litigation, both criminal and civil. Child custody issues, involving separation, divorce, neglect, termination of parental rights, the implications of child and spousal abuse, juvenile and adult justice services, corrections, and mandated treatment all fall under this definition. Forensic social worker may also be involved in policy or legislative development intended to improve social justice.
Functions of the forensic social work practitioner may include:
Forensic social work practitioners engage only in forensic activities within their areas of competence and expertise.
The first appointed Psychiatric Social Worker in London was in 1936. The British Association of Psychiatric Social Workers was inaugurated only in 1930. Most of the expertise in England and Wales has been concentrated within the Specialist Hospitals. – Ashworth, Rampton and Broadmoor. at Broadmoor Hospital the first qualified mental health social worker was not employed until 1969.
The Central Council for Training and Education in Social Work (which was responsible for promoting education and training in social work between 1971-2001) defined forensic social work as “social work with mentally disordered people who present, or are subject to, significant risk and as a consequence are, or could be, in contact with the criminal justice system…The key purpose of forensic social work is to hold in balance the protection of the public and the promotion of the quality of life of individuals and by working in partnership with relevant others to identify, assess and manage risk; identify and challenge discriminatory structures and practices; engage effectively and identify, develop and implement strategies.” 
Forensic social work has been done since at least 1899 coming out in part, of the settlement house movement, and the expansion of urban charity work.
The social worker bridges the gap between the two worlds of hospital and community.
In the United States the Forensic social worker has a variety of functions, including social assessments for various courts including Family Court, and providing assessments and aftercare for psychiatric hospitals.
In the U.K. the forensic social worker has several duties, including applications for hospital admission and when necessary, arrange aftercare (under s.117 of the Mental Health Act 1983) and social assessments. Psychiatric Social Worker's are now called Mental Health Professionals, Mental Health Social Worker, of if trained, an Approved Mental Health Professional are often located within Community Mental Health Team, hospital or based in the local authority. The social worker fulfills the role of the Social Supervisor to specify suitable accommodations for discharged patients, and to assess risk. They provide specialist social care reports to the Mental Health First Tier Tribunal.
The Department of Health in England currently identifies the following functions as being key to the social work role: • assessment; • care co-ordination; • report writing and presentation; • working with individuals and families; • working in collaboration with service users and carers; • undertaking social supervision with conditionally discharged patients and the supervision of those subject to supervision and in the case of those within forensic community teams, community treatment orders; • working with external agencies and multi-agency public protection arrangements (MAPPAs); • continuing professional development.
Social workers in the community are commonly appointed as 'social supervisors' to patients who are subject to conditional discharge has been discharge under section 41 of the Mental Health Act 1983. Social supervisors support the person in the community but also provide regular reports to the Ministry of Justice about their progress and may recommend their recall back to hospital.