The gangs matrix operated by the Metropolitan police has been found to be potentially discriminatory against black people.

A review of the database for the mayor of London, Sadiq Khan, found too many black people were on it compared with their likelihood of offending or their chances of being a victim.

The Met is overseen by Khan, which gives the findings more weight. The matrix contains the names and details of thousands of people whom the Met says pose a risk of committing gang violence or being victims.

The force has been ordered to radically reform the matrix and been given a year to do so.

The review, which was released on Friday morning, said: “The review does recognise that a gangs matrix is a necessary law enforcement tool for reducing violent crime in London.

“However, the review also identifies that the representation of young black males on the matrix is disproportionate to their likelihood of criminality and victimisation, and recognises that communities in London have deep reservations about how the matrix operates.”

The findings follow criticism from Amnesty International, which called the matrix a racialised war on gangs that has stigmatised black youngsters and left Britain breaking its human rights obligations.

In May, the Guardian revealed the matrix appeared to have caught up a significant number of individuals who, according to secret police assessments, did not pose a danger of committing violence.

An investigation by the information commissioner led to the issuing of enforcement notices against the Met for multiple and serious data protection breaches.

Those on the matrix can face sanctions relating to housing and other public services, with which the data about who is on the gangs list is shared.

Few complain if that is against violent gangsters, but the review found 38% of those on the matrix are assessed as posing no risk of committing violence.

The gangs matrix was launched after the 2011 riots, which the Conservative government initially blamed on gangs, but later reviews found the causes to be much wider. There has been controversy about how people came to be included on the matrix, how they could be removed and the way in which data is stored securely and applied consistently.

About 7,000 people have been on it since 2011, with around 3,800 on the list now. More are from an African-Caribbean background than the percentage of African-Caribbeans in London’s population.

The review said this level of disproportionality cannot be wholly explained by African-Caribbean levels of offending or being a victim.

Discussing potential racial discrimination, the review said: “We must acknowledge the possibility of conscious or unconscious bias against young black males in London – whether the term ‘gang’ is now heavily racially loaded and that this perception that a gang is often comprised of young black males, and ergo that young black males are often in a gang, either directly or unconsciously influences the enforcement focus of the police and subsequent actions of the justice service.

“However, proving or disproving this point in the case of the matrix is extremely difficult and would require analysis of the process and drivers behind every single action and decision leading to an individual’s addition, including embedded intelligence processes far wider than the matrix.”

The review found the matrix helped reduce offending and three-quarters of those on it were under the age of 25, and 80% were black.

In a statement, Khan said: “The review has shown that the gangs matrix can be an effective enforcement tool and is helping to tackle violence on our streets.

“But to many Londoners, the way it is applied and enforced is a cause for concern and it needs to be comprehensively overhauled to ensure it is used lawfully and proportionately.

“By implementing the review’s nine recommendations, the matrix can address the serious breaches of data protection laws and ensure only those at genuine risk of causing or being a victim of violence are included. It’s important these recommendations are carried out quickly and transparently to ensure Londoners have confidence in how it is used by the Met.”

Allan Hogarth from Amnesty International UK said: “This review should serve as a wake-up call for the police. A wide-ranging overhaul of this problematic database is long overdue to address some of the many serious concerns relating to racial profiling and data protection.

“In the last 12 months alone, the failings of the gangs matrix have been highlighted by Amnesty’s own research and a damning report from the Information Commissioner’s Office.

“There are also encouraging moves to tackle the inappropriate inclusion of people with no track record of violence, who nevertheless also end up targeted.

“However, the ongoing focus on the highly racialised concept of the ‘gang’ remains a matter of serious concern, which will continue to mean that young black men are hugely overrepresented on the database.

“It is now vital that these recommendations are implemented by the Met as soon as possible, and they demonstrate that young black men aren’t being unfairly and disproportionately targeted when tackling serious youth violence.”

Stafford Scott of the anti-racism charity the Monitoring Group, and an early critic of the discrimination involved in the gang matrix, said: “The impact of this process is what’s fuelling the violence as the young people on the database are policed in the most oppressive manner possible.

“This is what fuels the anger and frustration and this leads to the increase in violence that we are witnessing. It is not fit for purpose and must be scrapped.”

The Met said it “does not believe that the gangs matrix directly discriminates against any community and that it reflects the disproportionality of violent offenders and victims of violence that are also described in the report”.

Deputy assistant commissioner Duncan Ball said: “Young black men are disproportionately represented as victims of serious violence and this is an unacceptable position that needs to be addressed. The Matrix helps inform us in doing this.

“We accept that we have work to do in order to ensure public confidence in our use of information and data. The report today has further highlighted our commitment to working with the mayor’s office, the information commissioner’s office and other partners to ensure that the recommendations within the report are taken forward.”



