Spectator violence occurs all over the continent, but in the football countries Great Britain and Italy they have succeeded in reversing the trend in recent years. Law professor Geoff Pearson himself infiltrated supporters' clubs in the early 2000s.
Today, the groups are the subject of his research at the University of Manchester. According to him, the explanation for the decrease in violence lies partly in a better dialogue between supporters and the police – but also in tougher measures regarding access bans. Listen to SVT's Italy correspondent in the clip.