Metropolitan Police

The Met's page on the Gangs Violence Matrix says it was used from its inception in 2012 until its discontinuation took effect on 13 February 2024, that data was kept for 12 months to answer subject access requests, and that all data would be permanently destroyed on 13 February 2025. It describes the matrix as an intelligence tool scoring people on evidence of violence and weapons offences and on intelligence about access to weapons, grading each person red, amber or green for the risk (victims) or harm (offenders) they present; entry required identification as a gang member corroborated by reliable intelligence from more than one source. Computer Weekly, reporting the Information Commissioner's findings, said individuals were assigned an "automated risk score" and that "It is unclear what the scoring criteria are"; the Met page itself does not say whether scoring was automated. Police Professional reported on 13 February 2024 that the Met was decommissioning the matrix following "concerns about its disproportionality" and would use the existing Violence Harm Assessment, whose scoring draws on the Cambridge Harm Index and Office for National Statistics methods; neither source describes the Violence Harm Assessment as algorithmic or AI-based. The Met page cites its analysis of a cohort of 7,000 people who had been on the matrix for five years, which it says shows a sharp decline in sanctions once people were on the matrix, and notes concerns raised by Amnesty International.