It turns out that appearing in a music video, or simply associating yourself with a particular type of music online, can land you on a database purporting to show “propensity for violence”. The human rights group Amnesty International has produced a report on the Metropolitan police’s list of gang suspects, known as the gangs violence matrix. The report presents an abundance of evidence challenging the assumed relationship between serious youth violence and the policing of gangs. It provides a stark window into how flawed policy, discretionary everyday practice and unaccountable data-sharing, combine to hardwire racism into society.

The findings are damning. The study reveals how the labelling of young men, sometimes boys, almost exclusively from the black community, as “gang nominals” is often based on hunch or feeling. These uncorroborated assumptions then travel, appearing as “flags” on the case management systems of a range of agencies extending well beyond the criminal justice system. Individuals and their families become marked. The stigma leads to serious harms including criminalisation, imprisonment, exclusion from school, eviction from home, removal of children and deportation.

Amnesty’s report focuses solely on the matrix, the gangs list operated in London by the Met police. Yet research I have been involved in demonstrates that these practices exist beyond the capital. In 2012 Patrick Williams and I were asked by Manchester city council to profile those in gangs alongside those who had committed serious youth violence. The city was preparing to become one of the initial 33 local areas to implement the coalition government’s Ending Gang and Youth Violence policy.

Our analysis challenged the conflation of the policy areas. We found that while serious youth violence occurs in all communities, the distinct approach to policing gangs under the guise of fighting serious youth violence targets the black community almost exclusively. Three-quarters of those convicted of youth violence were white; nine out of 10 individuals on the Manchester gangs list were black or minority ethnic.

These facts contest the simple associations maintained in the dominant narrative about “gangs” and youth violence. Yet both national policy and local strategy, remain fixated with tying the solution to youth violence to a strategy of “fighting gangs”. This conflation is a political manoeuvre, whereby criminal justice agencies and politicians are able to both (re)define the problem of youth violence and create communities to be policed.

While singling out racialised communities for different policing practice is by no means new, the current practice of identifying and flagging young black men as gang nominals flows squarely from the government’s Ending Gang and Youth Violence policy. It is possible that all towns and cities where the policy has been implemented operate similar matrices or gang lists. That runs to 52 local authority areas in total. A public inquiry by the Information Commissioner’s Office, as recommended by Amnesty, would do well to follow the EGYV policy in seeking to examine these harmful practices.

While Amnesty concludes that the gathering and sharing of data from the matrix presents a risk of infringing human rights, such information-sharing has, in and of itself, become a key measure of the success of the EGYV policy.

Amnesty’s report exposes many of the damaging consequences of being labelled a “gang nominal”, but it is by no means exhaustive. In Manchester, we have seen the increased use of “threat to life” notices; one consequence of these can be the removal of children from the family home.

In a recent case, a local judge publicly called into question the use of police gang intelligence in a family court case where social services were looking to remove two brothers from their family on the basis of their older brothers’ reported gang association. Judge Iain Hamilton refused the request, arguing that the “court has no way of assessing how reliable or otherwise the police intelligence is”.

If only more judges were as circumspect about the use of police gang intelligence. Our national research, published in 2016, demonstrated how the racialised narrative of the “gang” becomes a central strategy for prosecution teams to secure joint enterprise convictions, even where defendants are not at the scene of a crime. A recent case in Manchester, in which 11 young black people were sentenced to 168 years in prison, bears the hallmarks of this process.

The prosecution QC called an officer from the police gang unit as an expert witness. He talked the jury through an extended version of the story of gangs in Manchester, seeking to connect the young people to Los Angeles gangs. Later in the trial, it was accepted that the majority of the young people had no convictions or intelligence connecting them to gangs. Yet the story was set, demonstrating how the racialised gang narrative can be a rich resource in the courtroom.

Rather than support an effective solution to youth violence – an urgent issue of harm in society, such policing and punishment strategies contribute to injustice and feed a lack of trust in the criminal justice system. The report highlights what those trapped in the matrix already know: that being on a gangs list marks you for different treatment.

This week E Tendayi Achiume, the UN’s special rapporteur on racism, is in the UK after human rights experts expressed serious concerns about racism rooted in the fabric of our society. By ending the use of all gang lists, we have an opportunity to start dismantling the harms done by institutional racism, beginning with those emanating from the criminal justice system.

• Becky Clarke is a senior lecturer in the Department of Sociology at Manchester Metropolitan University