HELSINKI (AP) — In one of the oldest unsolved criminal cases in Finland, a Finnish court has acquitted a 52-year-old Dane of murder and attempted murder over an attack on two German backpackers on a Baltic Sea ferry more than 30 years ago. Klaus Schelkle, aged 20, was killed and his 22-year-old girlfriend Bettina Taxis severely injured in a brutal attack while they were sleeping on the outer deck of the Viking Sally, en route from Stockholm in Sweden to the Finnish port of Turku in July 1987. The district court based in Turku, western Finland, said Wednesday the prosecutors had failed to prove their case against the defendant.