Al,he was a murderer, but his motive was religious and his crime was the mass murder of strangers which sets him apart from your average murderer.

Dave,
main findings of the analysis were that:
• violence in general, gun violence and fatal shootings in particular are concentrated in specific small areas of South Manchester
• victims of gun violence in South Manchester are mainly young, black or mixed race males, who themselves have criminal records
• those who have been victims of shootings are at increased risk of being a victim again
• perpetrators of serious gun violence in South Manchester are mainly young black or mixed race males, who have criminal records
• about 60 per cent of shootings are thought to gang related
• there are strong social norms (in particular in providing evidence in court) inhibiting co-operation with police enquiries into gang-related shootings, which undermine successful prosecution of offenders
• alliances are sometimes formed between South Manchester gangs, but conflict is endemic and easily triggered
• gangs in South Manchester are loosely turf-based
• there are significant differences in the origins, activities, and organisation of the four main South Manchester gangs known to the police, though members of all the gangs are involved in a wide range of criminal behaviour
• gang-related criminal behaviour includes drug-related offences, but only as one element of a patchwork of violent and non-violent crime
• gang membership is not just about criminality; for some young males it incorporates a credible lifestyle choice
• gang-membership comprises a mix of same-age local friendship groups, blood relatives and recruits
• the carrying of firearms by gang-members is part protective, and part symbolic, though they are also sometimes used in the commission of violent crime
http://webarchive.nationalarchives.gov.uk/20110220105210/rds.homeoffice.gov.uk/rds/pdfs2/crrs13.pdf