An Italian police officer was sentenced to six years in prison for killing a Lazio supporter two years ago.
Lazio fans in the Arezzo court reacted angrily to the manslaughter verdict after prosecutors had asked for a 14-year sentence for murder.
Luigi Spaccarotella shot dead 26-year-old Gabriele Sandri at a motorway service station following a scuffle between Lazio and Juventus fans on November 11, 2007.
The officer had argued he pointed his gun in the air to break up the fight and that a second shot went off by accident as he ran after the cars.
The incident prompted riots by Lazio supporters in Rome and fans of rival clubs which led to a general crackdown on football-related violence around the country.