Research QuestionDid gang members and gangs named by police in four separatecourt-ordered 24-month injunctions, issued at different times, reduce the frequency andharm of crimes they committed, and suffer fewer crimes against themselves as well?DataThe study examined criminal histories of 36 members of four gangs for a 36-month period before and a 36-month period after their respective injunctions. Data alsoincluded records of crimes committed against the gang members in the same timeperiods. Criminal activity was measured by arrests, station interviews, fixed penaltynotices and summonses. Days offenders spent in custody, which rose during the ganginjunction periods, were removed from denominators calculating rates, so that theestimates of changes in offender behaviour and victimisations are all based on theirdays at liberty and out of prison or jail.MethodsThe study compared the magnitude of change in both individual-level andgang-level measures of crime and victimisation from before to after the issuance of theinjunction as‘natural quasi-experiments’, with comparisons made to other gangs inLiverpool which had not been subjects of injunctions.FindingsAcross all 36 gang members, their individual offending counts dropped by70% in the 3 years after their gang injunctions, while the Cambridge Crime Harm Indexweight of the seriousness of their total crimes dropped by 61%. Fewer criminal eventswere attributed to 92% of the individuals in the second 3-year period than in the first,while only 8% increased their detected activity. Taking the four gangs as the unit ofanalysis, their offences dropped by 74% in the 3 years after the injunctions, while theirCrime Harm Index weight dropped by 70%. Victimisation of the gang members in their3-year post-injunction period dropped by 60% compared to the pre-injunction period.Comparisons between gangs with injunctions and gangs without showed downward