A force trialling software to help custody sergeants make decisions has faced criticism for basing information on “primitive” stereotypes.

Durham Police has paid global data broker Experian for UK postcode stereotypes built on 850 million pieces of information to feed into an artificial intelligence (AI) tool.

An investigation carried out by privacy organisation Big Brother Watch, shows the force is programming Experian’s “Mosaic” data, which profiles every adult in the UK to classify UK postcodes, households and stereotypes, into its Harm Assessment Risk Tool (HART).

The 66 Mosaic categories include “Disconnected Youth”, “Asian Heritage” and “Dependent Greys.”

Durham Police paid £25,913 for the data, to help predict whether a suspect might be at low, medium or high risk of reoffending, by placing the information into the AI system.

The code includes the “demographic characteristics” of each stereotype – characterising Asian Heritage as “extended families” living in “inexpensive, close-packed Victorian terraces”, adding “when people do have jobs, they are generally in low paid routine occupations in transport or food service”.

Disconnected Youth are characterised as “avid texters” whose “wages are often low” - with first names like “Liam” and “Chelsea”. Whilst people called “Stacey” are likely to fall under “Families with Needs” and are “on benefits.”

The names “Abdi” and “Asha” fell under the “Crowded Kaleidoscope” category, described as multi-cultural families likely to live in “cramped and overcrowded flats.”

Silkie Carlo, Director of Big Brother Watch, said: “For a credit checking company to collect millions of pieces of information about us and sell profiles to the highest bidder is chilling. But for police to feed these crude and offensive profiles through artificial intelligence to make decisions on freedom and justice in the UK is truly dystopian.

“We wouldn’t accept people going through our bins to collect information about us. Nor should we accept multi-billion pound companies like Experian scavenging for information about us online or offline, whether for profit or policing.

“Parliament should urgently consider what place this big data and artificial intelligence has in our policing.”

Sheena Urwin, Head of Criminal Justice at Durham Constabulary, said: “The force entered into a contract with Experian using Mosaic Public Sector to better understand our communities and to improve our engagement – the data they provided helped us do that. Our aim is to reduce harm to the communities we serve and improve life chances for the people we come into contact with.

“We must stress that the HART tool contributes to the decision-making process by assessing the risk of reoffending; however, the final decision remains with the custody sergeant.

“We are continuing to evaluate the research with our academic partners.”