Finland's South Ostrobothnia district court on Friday dismissed all charges brought against the police superintendent who questioned the Kauhajoki school shooter the day before the killing spree, allowing the man to keep his firearm.

Esa Puranen, representing the 10 victims' families, said he would appeal the ruling.

"This is the first round in a long fight," Mr Puranen said.

The prosecutor had pressed for a negligence fine, with the families saying the superintendent was guilty of ten counts of negligent homicide.

The court rejected the families' plea for more than 800,000 euros in damages.

Having been questioned by the superintendent in September 2008, Matti Saari killed 10 people at a vocational college in Kauhajoki before turning the licensed weapon on himself.

STT