AIAAIC - Met Police Gangs Violence Matrix

Gangs Violence Matrix

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Gangs Violence Matrix (GVM, or Gangs Matrix) was a controversial system detailing thousands of alleged street gang members in London, UK.

Established in 2012 in the wake of the 2011 London riots as a watchlist of people designated by police as “gang nominals”, the GVM was developed and operated by London's Metropolitan Police Service ('Met Police').

The system used one or more algorithms to rank and categorise people included on the database, based on the risk each 'gang member' posed to others, and the extent to which the police and partner agencies interacted with that person.

The GVM was subject to multipleresearch studies, investigations and legal reviews by Amnesty, Liberty, StopWatch and other rights organisations.

The MPS scrapped the Gangs Matrix in February 2024, replacing it with an adapted "violence harm assessment" (VHA) approach, which the Met described as more "precision-led".

System 🤖

Website: Gangs Violence Matrix 🔗
Operator: Metropolitan Police Service
Developer: Metropolitan Police Service
Country: UK
Sector: Govt - police
Purpose: Predict gang violence risk
Type: Database/dataset
Technique: Ranking algorithm

Documents 📃

Metropolitan Police (2018 rev 2023). Data Protection Impact Assessment (pdf) 🔗
Metropolitan Police (2018 rev 2022). Equality Impact Assessment (pdf) 🔗

Transparency and accountability 🙈

The Gangs Violence Matrix is seen to suffer from multiple transparency and accountability limitations, including:

Decision-making processes. Details of the matrix and its operation were not fully disclosed to the public.
Scoring system. The criteria and algorithms used to score and categorise individuals were not transparent.
Data sharing. Questions surround how information from the matrix was nshared with other agencies.
Independent oversight. There was insufficient external review of the matrix's implementation and impacts.
Complaints and appeals process. Individuals struggled to know if they were on the matrix or how to contest their inclusion.
Impact assessments. There was limited public information on how the matrix's effectiveness was evaluated.

Risks and harms 🛑

The Gangs Violence Matrix was criticised for being inaccurate, unfair and discriminatory.

Incidents and issues 🔥

Incidents associated with the Gangs Matrix include:

September 2017. 14-year-old Corey Junior Davis, known as CJ, was shot dead in Forest Gate
November 2022. A young Black male was deported after wrongly being labeled a gang member, according to his solicitor
A young man was wrongly labeled as a gang member on Gangs Matrix and was denied a place at university as a result.

Issues associated with the Gangs Matrix:

2022. A report by the UK's Independent Review of Prevent finds that the Gangs Matrix has been used to unfairly target and stigmatise certain communities, and recommends that the database be reformed
2022. The Independent Office for Police Conduct (IOPC) finds that the MPS has made some progress in addressing concerns about the Gangs Matrix, but that more work is needed to ensure that it is fair and effective
February 2022. Met Police faces legal action over "racist" Gangs Matrix database 🔗
2020. Amnesty finds that the Gangs Matrix is still being used to unfairly target and stigmatise young black men
November 2018. UK information commissioner: Gangs Matrix potentially breaks data protection law 🔗
September 2018. Police monitoring group Stopwatch report argues the Gangs Matrix is "racially biased"
May 2018. Amnesty argues Gangs Matrix is discriminatory and "not fit for purpose" 🔗
September 2017. Government review concludes Gangs Matrix is inaccurate, discriminatory 🔗
January 2017. Gangs Matrix data leak puts young Londoners in "serious danger" 🔗