Italian police on Tuesday arrested a second person in connection with the February 2007 murder of a police officer during a soccer riot in Sicily.
Daniele Micali, 21, was taken into custody on suspicion of helping 19-year-old Antonino Spaziale attack the officer during the Sicilian derby between Catania and Palermo.
Spaziale has been held for more than a year after he was identified in video footage of the February 2 riot.
Officer Filippo Raciti, 38, received fatal internal injuries as Catania fans fought police with metal bars and powerful firecrackers while trying to get at their Palermo rivals.
Police say the two fans hit the police officer with pieces of metal piping ripped from a stadium toilet.
Raciti died later in hospital of liver injuries, leaving a wife and two children.
The riot led to a hooligan clampdown that forced many Serie A clubs to close their doors until they met new security requirements.
Stadium violence has been curbed, largely by following an English steward-based approach, but hooligans have started facing off at other places, especially motorway service stations.
Two fans have been killed this season at service stations - a Lazio supporter shot by a police officer on November 11 and a Parma supporter crushed by a coach three days ago.
The deaths took place after or during alleged hooligan incidents.
The death of the Lazio fan sparked rioting across the country and a rampage around Rome's Olympic stadium, where cars were burned, police stations attacked and the headquarters of the Italian Olympic Committee damaged.
Another security crackdown took place, focusing on identifying hooligans and increasing stadium bans.
The recent Parma fan's death has led to fresh moves for more travel bans, more pre-match security along motorways, and the introduction of ID cards aimed at rooting out violent elements.
Commenting on Tuesday's arrest of Micali, agent Raciti's widow Marisa Grasso said: ''Arrests aren't going to give me my husband back. A lot of work has to be done to change things.
''But the death of the Parma fan shows nothing has changed''.
