This is a very good giallo movie, similar to Friedkin's 'Cruising', although the victims are all female here. 'Ripper' is a film submerged in sleaze and depression. Not a film you would want to watch with your girlfriend: misogynic content is strong, especially the scene where the girl is mutilated with a razor blade. The killer's knife is an obvious phallic symbol, but surprisingly there is only one rape scene.
If you prefer American fantasy slashers in the vein of 'Friday the 13th', stay far away.