UK Met Police Gangs Violence Matrix
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Gangs Violence Matrix (GVM) is a controversial database of thousands of alleged street gang members developed and operated by London's Metropolitan Police Service ('Met Police').
Introduced in 2012, the GVM uses one or more algorithms to rank and categorise people included on the database, based on the risk each 'gang member' poses to others, and the extent to which the police and partner agencies interact with that person.
Operator: Metropolitan Police Service (MPS)
Developer: Metropolitan Police Service (MPS)
Country: UK
Sector: Govt - police
Purpose: Predict gang violence risk
Technology: Ranking algorithm
Issue: Bias/discrimination - race, ethnicity, income, geography; Accuracy/reliability; Privacy
Transparency: Governance; Complaints/appeals; Black box
Risks and harms 🛑
The Gangs Violence Matrix has been criticised for being inaccurate, unfair, and discriminatory, as well as for exhibiting poor transparency and accountability.
Incidents 🔥
The GVM (also known as 'Gangs Matrix') has been subject to multiple investigations, research studies, and legal reviews by Amnesty, Liberty, StopWatch, and other organisations.
It has also been the subject of a high-profile two-part review (part one, two - pdf) ordered by London mayor Sadiq Khan, and an independent review commissioned by then UK Prime minister David Cameron of England and Wales' criminal justice system by David Lammy MP.
These studies variously conclude that the GVM is inaccurate, discriminates against racial and ethnic minorities, and is, according (pdf) to Amnesty, 'unfit for purpose'.
In 2018, the Met Police's use of Gangs Matrix was served (pdf) with an enforcement notice by the UK privacy commissioner for 'potentially' breaking data protection laws, and for its failure to distinguish victims of crime and offenders. The notice was lifted in 2021.
In October 2022, the Met Police announced it had removed over 1,200 names from the list.
Transparency and accountability 🙈
The Gangs Violence Matrix is seen to suffer from multiple transparency and accountability limitations, including:
Lack of public scrutiny. Details of the matrix and its operation are not fully disclosed to the public.
Opaque scoring system. The criteria and algorithms used to score and categorise individuals are not transparent.
Data sharing opacity. Questions surround how information from the matrix is shared with other agencies.
Limited independent oversight. There is insufficient external review of the matrix's implementation and impacts.
Opaque appeals process. Individuals struggle to know if they're on the matrix or how to contest their inclusion.
Unclear removal process. The procedure for removing individuals from the matrix lacks transparency.
Impact assessment gaps. There's limited public information on how the matrix's effectiveness is evaluated.
Legal, regulatory 👩🏼⚖️
ICO Enforcement Notice (pdf)
Investigations, assessments, audits 🧐
MOPAC (2022). Review of the Metropolitan Police Service Gangs Violence Matrix – Second Annual Review (pdf)
MOPAC (2021). Review of the Metropolitan Police Service Gangs Violence Matrix: Update on the implementation of the MOPAC recommendations (pdf)
Lammy D. (2018). The Lammy Review
MOPAC (2018). Review of the Metropolitan Police Service Gangs Matrix (pdf)
Met Police (2018 rev 2023). Data Protection Impact Assessment (pdf)
Met Police (2018 rev 2022). Equality Impact Assessment (pdf)
Research, advocacy 🧮
Stanford HAI (2023). 2023 AI Index Report - 3.2 AI Incidents (pdf)
Pyrooz D.C., Decker S., H. (2019). Competing for Control. Gangs and the Social Order of Prisons
Amnesty (2018). Trapped in the Matrix: Secrecy, stigma, and bias in the Met’s Gangs Database (pdf)
Williams P., StopWatch (2018). Being Matrixed: The (Over)Policing of Gang Suspects in London
Scott S., The Monitoring Group (2017). The War on Gangs
Williams P., Clarke B., Centre for Crime and Justice Studies (2016). Dangerous Assocations: Joint enterprise, Gangs and Racism (pdf)
Bridges L. (2015). The Met Gangs Matrix: Institutional Racism in Action
News, commentary, analysis 🗞️
https://www.independent.co.uk/news/uk/home-news/met-police-gangs-matrix-database-b2004293.html
https://www.independent.co.uk/news/uk/home-news/met-police-gangs-matrix-database-b2006051.html
https://www.theregister.com/2019/02/05/cops_told_to_scrap_algorithms_for_policing_work/
https://www.wired.co.uk/article/gangs-matrix-violence-london-predictive-policing
https://www.theregister.com/2018/11/16/ico_gangs_matrix_decision/
Page info
Type: System
Published: February 2022
Last updated: May 2024