At least 14 UK police forces, including the Metropolitan Police and Greater Manchester Police, have used or intend to use computer programs to predict where crime will be committed and by whom, according to new research published by the human rights group, Liberty.
The new report, “Policing by Machine”, collates the results of 90 Freedom of Information requests sent to every force in the UK. It reveals that 14 forces are using, have previously used or are planning to use algorithms which ‘map’ future crime or predict who will commit or be a victim of crime, using police data.
The report exposes police algorithms, which Liberty says entrench pre-existing discrimination, and direct officers to patrol areas which are already disproportionately over-policed.
The human rights group says there is a severe lack of transparency with the public given very little information as to how predictive algorithms reach their decisions – and that “even the police do not understand how the machines come to their conclusions”.
Individual risk assessment programs predict how people will behave, including whether they are likely to commit – or even be victims of – certain crimes. Predictive mapping programs use police data about past crimes to identify “hot spots” of high risk on a map. Police officers are then directed to patrol these areas.
Liberty says the computer programs used are not neutral, and that some are even capable of learning, becoming more autonomous in their predictions and entrenching pre-existing inequalities while disguised as cost-effective innovation.
The Liberty report provides an example of the technology used to predict crime. Durham Constabulary has used a program called Harm Assessment Risk Tool (HART) since 2016. It uses machine learning to assess the likelihood of a person committing an offense, but is designed to overestimate the risk.
HART bases its prediction on 34 pieces of data, including personal characteristics such as age gender and postcode, and it has also considered factors such as “cramped houses” and “jobs with high turnover” when deciding the probability of a person committing crime.
Meanwhile, Avon and Somerset Police’s risk assessment program predicts the likelihood of a person perpetrating or suffering serious domestic violence or violent sexual offences.
Liberty makes a number of recommendations in its report, including investment in digital solutions for policing which focus on developing programs that actively reduce biased approaches to policing.