Bristol police developed a crime prediction system that includes data on nearly half a million residents, but at least two of its risk-scoring models were quietly abandoned due to concerns about their reliability. The Think Family Database, launched in 2016 by Bristol City Council and Avon and Somerset Police, collects sensitive information such as police intelligence reports, mental health records, and housing status. Officials used machine-learning models to assign risk scores to thousands of adults and children, aiming to create a 'picture of threat, harm, and risk' in the region. 'I essentially dump all that data in a big bucket and stir it with a data-science spatula, and we come out with a lovely risk score for everybody,' said a police data scientist at an event in early 2022.
The predictive analytics program included at least 23 models to assess risks like burglary, missing persons, and domestic abuse. One senior officer described creating a 'league table' of the area's most dangerous criminals, referencing the Offender Management App, which holds data on around 300,000 people. John Pegram, leader of a local police accountability group, learned about the app in 2023 and suspected he might be included. After filing a data request in early 2024, he was confirmed to be on the app but received no further details about how his data was used. Like many others, he remained unsure about his risk score or how it might affect his interactions with authorities.
The investigation by WIRED and other outlets revealed that at least two risk-scoring models were abandoned after Bristol City Council staff deemed them untrustworthy. Previously unreported documents showed government inspectors and independent reviewers highlighted a lack of transparency and warned that the systems could undermine public trust. Police data disclosed to WIRED, comprising over 36,000 model performance scores, appeared to show 'genuinely poor predictive performance' according to an independent analyst. These findings come as the UK moves toward wider use of predictive analytics and AI in policing, with Andy Marsh, former chief constable of Avon and Somerset, leading efforts to integrate AI tools into police work.
Source: wired
