His career spanned over 60 years in work pertaining to forensic psychiatry, and his appointments included positions at the universities of Leeds, Loughborough, Leicester and Birmingham.

[1][2] Prins' career, much of which is detailed in his book Mad, Bad and Dangerous to Know: Reflections of a Forensic Practitioner (2010),[3] covered over 60 years in work pertaining to forensic psychiatry, and his appointments included university positions, HM probation inspectorate, parole board engagement, and involvement in mental health review tribunals and the mental health act commission.

[6][4] Subsequently, he was posted to Stamford House, a remand home for boys, where he met Peter Duncan Scott, a forensic psychiatrist who influenced him enough that Prins later dedicated his first edition of Offenders, Deviants, or Patients?

(1993), one of the 1990s reports which looked at the experiences of young black men of African-Caribbean origin within the Criminal Justice System (CJS) and mental health services.

[10][11] Also known as 'The Prins Inquiry', it investigated the circumstances of Blackwood's death in August 1991 at Broadmoor Hospital, and was "clear" that service provision featured racism.

[12][10] The second was the Report of the Independent Panel of Inquiry into the Circumstances Surrounding the Absconsion of Mr. Holland From the Care of the Horizon NHS Trust on 19 August 1996.

[8] In 1999, Mentally Disordered Offenders: Managing People Nobody Owns, edited by David Webb and Robert Harris, was compiled by his peers.

[15] Prins' 2013 publication, Psychopaths: an Introduction, was based on his huge experience and includes a quote by judge John Geoffrey Jones on classifying criminal deeds.